gaelco/gaelco2.cpp: Fix metadata, Cleanups

[cam900]

• Fix metadata for snowboar* matches as copyright screen and 'OMK presents' screen
• Fix metadata for bang* matches as copyright screen
• Split snowboar state class for reduce optional finder
• Fix typename consistency
• Correct variable types
• Make some variables constant
• Fix spacing
• Fix ROM region naming
• Use C++ style single line comments
• Reduce literal tag usage
• Reduce duplication
• Reduce unnecessary line
• Fix filename in comment
• Fix typo