Fix mantis 2921: start mainhall music when leaving the credits state

git-svn-id: svn://svn.icculus.org/fs2open@10507 387891d4-d844-0410-90c0-e4c51a9137d3
Fixed oversight in r10490.

git-svn-id: svn://svn.icculus.org/fs2open@10508 387891d4-d844-0410-90c0-e4c51a9137d3
separate file selection into its own utility method

git-svn-id: svn://svn.icculus.org/fs2open@10509 387891d4-d844-0410-90c0-e4c51a9137d3
add header comment
use logger instead of System.out

git-svn-id: svn://svn.icculus.org/fs2open@10510 387891d4-d844-0410-90c0-e4c51a9137d3
since we don't actually make special provisions for the interrupt here, don't look for it

git-svn-id: svn://svn.icculus.org/fs2open@10511 387891d4-d844-0410-90c0-e4c51a9137d3
a couple of tweaks

git-svn-id: svn://svn.icculus.org/fs2open@10512 387891d4-d844-0410-90c0-e4c51a9137d3
add capability to run external commands on the host system

git-svn-id: svn://svn.icculus.org/fs2open@10513 387891d4-d844-0410-90c0-e4c51a9137d3
only save root VP hash when DirectoryTask is nearly complete
add another interrupt check

git-svn-id: svn://svn.icculus.org/fs2open@10514 387891d4-d844-0410-90c0-e4c51a9137d3
add extra mod nodes for installing OpenAL and installing FS2 from GOG packages

git-svn-id: svn://svn.icculus.org/fs2open@10515 387891d4-d844-0410-90c0-e4c51a9137d3
add some missing imports

git-svn-id: svn://svn.icculus.org/fs2open@10516 387891d4-d844-0410-90c0-e4c51a9137d3
Remove gcc warnings (unused & shadow)

git-svn-id: svn://svn.icculus.org/fs2open@10517 387891d4-d844-0410-90c0-e4c51a9137d3