all: Remove redundant headers

https://bugzilla.gnome.org/show_bug.cgi?id=731865
appdata: Now we support Facebook too
appdata: Mark name and summary to be translatable
appdata: Set each li translatable instead of the whole <ul>

https://bugzilla.gnome.org/show_bug.cgi?id=708039
Updated Hebrew translation
Updated Greek translation
Add application-specific theme extensions

This used to live in gnome-themes-standard, but with the move of
Adwaita to GTK+, it needs to find a new home.

https://bugzilla.gnome.org/show_bug.cgi?id=733011
preview-view: Rearrange the code to allow multiple view widgets

Fixes: https://bugzilla.gnome.org/726505
preview-view, preview-nav-buttons: Sliding transition between photos

Fixes: https://bugzilla.gnome.org/726505
preview-nav-buttons: Restrict keynav within the bounds of the model

We hide the buttons when after reaching one end of the model. We
should also disable keyboard navigation in such cases.

Fallout from edc439c92044b04395e88391d8379f4911eb65bc

Fixes: https://bugzilla.gnome.org/726685
gegl-gtk-view-helper: Use cairo API to calculate stride

Fixes: https://bugzilla.gnome.org/733355
gegl-gtk-view-helper: Fix vertical stripes in the rendered image

Fixes: https://bugzilla.gnome.org/733355
theme: Add CSS snippet for GdMainIconView

Fixes: https://bugzilla.gnome.org/733011
embed: Print a diagnostic if loading the item failed
Updated Brazilian Portuguese translation