mpd: update to 0.18.11.
tinc: update to 1.0.24.
notmuch: update to 0.18.
dovecot: update to 2.2.13.
gource: update to 0.42.
hooks/pre-configure: new hook to generate foo-config wrappers in cross builds.

Script wrappers are created in ${wrksrc}/.xbps/bin and this path is appended
to make the configure scripts detect them.

This avoids adding build deps in hostmakedepends, as well as avoiding modifying
templates to specify the path to the script.

Currently this only creates a wrapper for "icu-config", but can be extended
easily to create more wrappers (freetype, libxml, etc).
webkitgtk: update to 2.4.2.
gtk+3: update to 3.12.2.
libevdev: update to 1.2 (soname bump).
libinput: revbump due to libevdev soname bump.
xf86-input-synaptics: update to 1.8.0.
hooks/script-wrapper: create libgcrypt-config wrapper.
gcr: add gir build option; cross build support.
gcr: repair cross (needs glib-devel).
midori: cross build support.
telepathy-glib: cross build support.
xombrero: revbump to trigger autobuilds.
hooks/script-wrapper: create freetype-config wrapper; simplify code.
SDL_ttf: no need to depend on host freetype anymore.
SDL_image: use pkg-config to detect SDL.