adjust colors: Fix the undo symbols in RTL

https://bugzilla.gnome.org/show_bug.cgi?id=723542
rotate image: Fix the undo symbols in RTL

https://bugzilla.gnome.org/show_bug.cgi?id=723542
sharpen: Fix the undo symbols in RTL

https://bugzilla.gnome.org/show_bug.cgi?id=723542
toolbox: Fix the undo and the redo symbols in RTL

https://bugzilla.gnome.org/show_bug.cgi?id=723542
script editor: help buttons don't work

https://bugzilla.gnome.org/show_bug.cgi?id=722925
ctrl+p doesn't work

https://bugzilla.gnome.org/show_bug.cgi?id=722707
Updated Hungarian translation
Updated Greek translation
call gdk_notify_startup_complete before showing the windows
comments: do not emit a changed event if the file is not changed
added AppData file for GNOME Software Center

https://bugzilla.gnome.org/show_bug.cgi?id=722770
Updated Polish translation
Updated Czech translation
Updated Lithuanian translation
Updated Brazilian Portuguese translation
Updated Spanish translation
Updated German translation
comment view: fixed selected text color
emit the image_changed signal only when the zoom level is ready

[bug #722631]
image viewer page: init all the attributes