Implement std::hash for Str::StringRef
Add framework/Resource and use it for audio/Sample

This is somewhat WIP, there are a few blocking TODOs,
especially the one near the declaration of Manger::Register
Add the S_{Begin/End}Registration syscalls and use them in cgame
Resource: introduce a Handle WIP for c&c
Fix compilation of std::hash<Str::StringRef>
Fix a stupid 'optimization' in std::hash<Str::StringRef>
Update the doc of Resources for Handles
Packaging updates; mostly file location changes.
Merge branch 'master' into debian
Fix memory leak introduced in texture compression merge
One more main→pkg change.
Changelog update.
Merge branch 'master' into debian
Enable USE_VOIP and remove unnecessary build dependency on xvidcore.
Avoid light sampling outside the light grid.
Fix the copyrights
Add torrent downloader shell script for assets.
Use torrent download script in archlinux package.
Fix Archlinux package cache directory, fix unvanquished.install output.
Mark fs_extrapaks as a startup variable