Changeset for compilation + broken runnage of luakit with libwebkit3.

It works reasonably well, with the following exceptions;
   * at least one event handler is broken.
   * Window resizes to fit content (I assume; I'm running a tiling
     window manager so I don't knwo for certain).
   * The command input field does not display. This may be a side effect
     of windows resizing to fit content.
compiles with -DG{D,T}K_DISABLE_DEPRECATED
prevent webview to allocate size of the whole content
[vh]box_new() -> box_new()
webkit3 support: compiles and works with USE_GTK3=1
optional conversion of keyval
mkdir format should use rstring.format
favicon as window icon
Merge remote branch 'upstream/develop' into favicons
merged keyboard_layout
Merge branch 'favicons' into liaonau
Merge branch 'liaonau' into develop

some nice branches
Merge remote-tracking branch 'origin/webkit3' into develop

self explanatory
removed gtk2