Add WebKit1 compatibility module

Building WebKit twice will not be fun, but nothing else to do unless we
want all of these applications to remain broken.

Also, remove GIMP's suggests on WebKit since it can only use
webkitgtk-1.0 (not to be confused with webkitgtk-3.0, the version of
WebKit 1 we provide compatibility with).
world-3.14: liferea moved to github
world-3.14: fix librsync