Add application menu.

Use menu model for left GtkMenuButton.

Use menu model for right edit menu.

Make buttons of header bar quadratic.

Fix typo in 'deamon'.

Fix sensitivity of "display daemon output" item.

Move UI definition to glade file, completely.

Fix mysterious bug that does not show app menu.

Set spacing to multiple of 6. Delete GtkAlignment.

Delete left menu button in HeaderBar.

Use set_app_menu() only for HeaderBar mode.

Use 16 pixel icon for ST button.
Use Action instead of signal handler in menus.
Add case distinction for different platforms.
Add GtkSeparator between menu bar and content.
Remove margins and add borders.
Added safe-upgrade file 

This file will prevent app from upgrading daemon to unsupported version later.
Fix bug with HeaderBar case distinction.
Fix: Correct error message placeament without headerbar
Fix: Label on error messages should be left-aligned
Merge branch 'master' of https://github.com/kozec/syncthing-gui
Use HeaderBar on any platform.
Merge branch 'menu' of https://github.com/jaystrictor/syncthing-gui into jaystrictor-menu

Conflicts:
	syncthing_gtk/app.py
Merge branch 'jaystrictor-menu'
Merged autoupdater from branch
FindDaemonDialog: Disable 'save' button durring download
Prevent downloader / autoupdater from downloading unsupported Syncthing version; Uses Syncthing_* git tags in Syncthing-GTK repository
UI fix: Removed 'label' text from one label, it was displayed durring startup
Little cleanup in app.glade, removed few warnings
Fix: Sensitivity of traditional header menu button
Added option to toggle menu icons in UI Settings (ignored on Gnome); Re-enabled Window menu button relief in Windows; Set appmenu to be used only with Gnome