try to cache the build dependencies
don't require InfDeath for Explodes

closes #5336
Check proc's health before (un)docking. Fixes #5338
Merge pull request #5340 from obrakmann/fix5338

Check proc's health before (un)docking. Fixes #5338
Merge pull request #5337 from Mailaender/explodes-infdeath-null

Fixed Explodes never triggering
Remove the deprecation notice from the old Lua interface

Fixes #5332.  The impending deprecation should probably still be
mentioned in the release notes.
Merge pull request #5344 from obrakmann/remove-lua-deprecation-notice

Remove the deprecation notice from the old Lua interface
Merge pull request #5335 from Mailaender/travis-cache

Try to cache the build dependencies for Travis CI
Fixes crash when joining multiplayer lobby

Fixes crash when joining a multiplayer lobby caused by recent spawn
choice changes.
Merge pull request #5352 from Squiggles211/mp_lobby_fix

Fixes lobby crash when joining MP game
separate content install from loadscreen
unify install from CD logic
unify music install and add a download option

closes #4759
fix Tiberian Dawn CD rip logic

closes #4424
add TrimOrDefault to avoid NREs
unmount all to avoid write permission problems

fight the new caching mechanism and M$ WindowsTM file systems