Hexen: Fixed typos in texture precache group defs
Hexen: Removed some unnecessary cruft from anim.ded
Fixed|Plugins: Usage of extern "C"

Clang was warning about duplicate externs.
Server: Tweaked server log output
Amethyst: Imported the latest sources from the Mercurial repository

It is good to have all the tools included as part of the main source
distribution. The separate Amethyst repository won't be discontinued,
though.
Merge branch 'master' into mapdata-c++