OSX: Allow user to display hidden files in the browser dialog
OSX: Fix memory leaks
SCUMM: Clean-up of Roland GS code

1. Remove _sc55 bool. All Roland GS-capable devices have MT-32 sound/drum maps, so they should always be used when _enable_gs is set.
2. Always enable _native_mt32 if Roland GS mode is selected. I don't know why I never did this originally, since _enable_gs is automatically disabled for SCUMM v6+ games that use General MIDI tracks instead of MT-32 music.
3. Set master tune for GS devices to 442.0kHz. This is the master tune setting for the MT-32.
GUI: Update Roland GS description in MT-32 tab

Clarified the Roland GS settings. The current description is only partially accurate and confusing at best.
NEVERHOOD: Fix incorrect dark palette in Scene2206
CGE: Introduce gametype
Revert "DRASCULA: Fix the comment of the Debian repacked Italian version"

This reverts commit d06a6542249ae18ec4b43ffb7ac4e5273baf3fd7.
Revert "DRASCULA: Add detection entries for the Debian repacked versions (bug #3612236)"

This reverts commit f0071c65adf72f0fda07395b19b28a7e730b619a.
NEVERHOOD: Add neverhood.dat to dist files.
GIT: Ignore create_{neverhood,tony}
NEVERHOOD: Fix uninitialized variable.
I18N: Update Polish translation (from patch #3613727)
I18N: Regenerate translations data file
HOPKINS: Update detection to avoid as much as possible the use of executables
WINTERMUTE: Fix erroneous _gameRef in BaseQuickMSG

CID 1002323
PSP: Remove leftover debug statement to non-existant variable.

This would cause a compilation error when the __PSP_DEBUG_PRINT__
define was enabled for debugging as the variable is non-existant.
HOPKINS: Fix bug #3613819 - Crash when loading a savegame in Win95 Demo
Merge pull request #307 from criezy/filebrowser-hidden-osx

OSX: Allow user to display hidden files in the browser dialog.
GUI: Add missing include for IBAction

Hopefully will fix compilation on older Mac versions
GUI: Fix the spelling of some variable/class names