Fix incorrect usage of no_asm in SConstruct

zico switched the variable to 'asm' in dac257e, so referring to no_asm
has no effect now.
Normalize comments and whitespace to match D2X
config.c: mark global strings as const
Remove last bits of HOSTAGE_FACES code

As far as I can tell, this never shipped, so remove it.
Remove PSX_BUILD_TOOLS code

This is never activated.
Remove DPMI support and BITMAP_SELECTOR
Rename D1XMAJOR/D1XMINOR/D1XMICRO to VERSION_MAJOR/VERSION_MINOR/VERSION_MICRO
Rename D1XMAJORi/D1XMINORi/D1XMICROi to DXX_VERSION_MAJORi/DXX_VERSION_MINORi/DXX_VERSION_MICROi
Overload argument lookup to allow version-specific names
Move command line settable values into class Settings
Simplify copying in compiler environment variables
Collapse ogldefines handling

ogldefines is always set to ['OGL'], so remove the definitions of it and
just set that value explicitly when OpenGL is used
Move platform-specific settings into specialized settings classes
Remove ineffective LINKFLAGS assignment
Move SCons rules into wrapper classes