Valama: Use webkit2gtk-3.0 vapi from 0.25.1 revision.

 * libvala-0.26 only provides webkit2gtk-4.0, so every Vala version needs this
   custom vapi.
   Thanks to inizan-yannick.
Guanako: Fix spelling mistake.
Merge remote-tracking branch 'origin/master' into debian
Fix lintian warnings. Decrease version to 0.2 again.

 * Add missing deps: libwebkit2gtk-3.0-dev, librsvg2-bin
 * Standards version bump to 3.9.5.
 * Documentation package debhelper deps ${misc} and architecture independent.
   Also update short description.
 * Remove debian revision from symbols file.
 * Keep autogen.sh executable.
 * Lintian override for autotools template copyright file.