removed unused code and fixed some warnings

src/Assistant.vala

@@ -39,7 +39,6 @@ namespace Webpin {
         private Gtk.Entry app_name_entry;
         private Gtk.Entry app_url_entry;
         private Gtk.Entry icon_name_entry;
-        private Gtk.ComboBox app_category_combo;
         private Gtk.CheckButton save_cookies_check;
         private Gtk.CheckButton save_password_check;
         private Gtk.Popover icon_selector_popover;
@@ -72,7 +71,7 @@ namespace Webpin {
 
             //welcome message
             message = new Gtk.Label (_("Create a new web app with webby"));
-
+            message.get_style_context ().add_class ("h2");
             //app information
             icon_button = new Gtk.Button ();
             icon_button.set_image (new Gtk.Image.from_icon_name (default_app_icon, Gtk.IconSize.DIALOG) );
@@ -257,12 +256,12 @@ namespace Webpin {
 		            }
                 }
 
-                if (pix!=null){
+                if (pix != null){
                     preview.set_from_pixbuf (pix);
                     file_chooser.set_preview_widget_active (true);
                     file_chooser.set_preview_widget (preview);
                 } else {
-                    file_chooser.set_preview_widget (null);
+                    file_chooser.set_preview_widget_active (false);
                 }
             });
 

src/DesktopFile.vala

@@ -56,7 +56,11 @@ namespace Webpin {
             this.icon = icon;
 
             file = new GLib.KeyFile();
+            try {
                 file.load_from_data (template, -1, GLib.KeyFileFlags.NONE);
+            } catch (Error e) {
+                warning (e.message);
+            }
             //TODO: Category
             file.set_string ("Desktop Entry", "Name", name);
             file.set_string ("Desktop Entry", "GenericName", name);
@@ -68,31 +72,53 @@ namespace Webpin {
 
         public DesktopFile.from_desktopappinfo(GLib.DesktopAppInfo info) {
             file = new GLib.KeyFile();
+            try {
                 file.load_from_file (info.filename, KeyFileFlags.NONE);
+            } catch (Error e) {
+                warning (e.message);
+            }
             this.name = info.get_display_name ();
             this.icon = info.get_icon ().to_string ();
+            try {
                 this.url = file.get_string ("Desktop Entry", "Exec").substring (31);
+            } catch (Error e) {
+                warning (e.message);
+            }
         }
 
         public bool edit_propertie (string propertie, string val) {
-            string filename = GLib.Environment.get_user_data_dir () + "/applications/" +file.get_string("Desktop Entry", "Name") + "-webpin.desktop";
+            bool return_value = false;
+            try {
+                string filename = GLib.Environment.get_user_data_dir () + "/applications/" + file.get_string("Desktop Entry", "Name") + "-webpin.desktop";
                 file = new GLib.KeyFile();
                 file.load_from_file (filename, KeyFileFlags.NONE);
                 file.set_string ("Desktop Entry", propertie, val);
-            return file.save_to_file (filename);
+                return_value = file.save_to_file (filename);
+            } catch (Error e) {
+                warning (e.message);
+            }
+
+            return return_value;
         }
 
         public GLib.DesktopAppInfo save_to_file () {
+            GLib.DesktopAppInfo return_value = null;
+            try {
                 string filename = GLib.Environment.get_user_data_dir () + "/applications/" +file.get_string("Desktop Entry", "Name") + "-webpin.desktop";
                 print("Desktop file created: " + filename);
                 file.save_to_file (filename);
-            return new GLib.DesktopAppInfo.from_filename (filename);
+                return_value = new GLib.DesktopAppInfo.from_filename (filename);
+            } catch (Error e) {
+                warning (e.message);
+            }
+
+            return return_value;
         }
 
         public bool delete_file () {
+            try {
                 string filename = GLib.Environment.get_user_data_dir () + "/applications/" +file.get_string("Desktop Entry", "Name") + "-webpin.desktop";
 	            File file = File.new_for_path (filename);
-	        try {
 		        file.delete ();
 	        } catch (Error e) {
                 print(e.message + "\n");

src/WebBar.vala

@@ -50,11 +50,11 @@ namespace Webpin {
             url_entry.show_all();
 
             share_button = new Gtk.Button.from_icon_name ("application-menu-symbolic", Gtk.IconSize.SMALL_TOOLBAR);
-            share_button.margin_left = 15;
+            share_button.margin_start = 15;
             share_button.show_all ();
 
             back_button = new Gtk.Button.from_icon_name ("go-next-symbolic-rtl", Gtk.IconSize.SMALL_TOOLBAR);
-            back_button.margin_right = 15;
+            back_button.margin_end = 15;
             back_button.show_all ();
 
             pack_start (back_button);

src/Widgets/ApplicationIcon.vala

@@ -31,9 +31,7 @@ namespace Webpin {
 
         Gtk.Image image;
         Gtk.Label label;
-        Gtk.MenuButton conf_btn;
         Gtk.Box box;
-        Gtk.ActionGroup action_group;
 
         internal DesktopFile desktop_file { get; private set; }
 
@@ -93,8 +91,12 @@ namespace Webpin {
 
         private void set_icon (string icon) {
             if (File.new_for_path (icon).query_exists ()) {
-                var pix = new Gdk.Pixbuf.from_file (icon);
+                Gdk.Pixbuf pix = null;
-
+                try {
+                    pix = new Gdk.Pixbuf.from_file (icon);
+                } catch (Error e) {
+                    warning (e.message);
+                }
                 int new_height = 64;
                 int new_width = 64;
                 int margin_vertical = 0;