Revert "Move main/bmread.c to be sorted in SConstruct"

This reverts commit e3dd328e66c33ecc5218307b87b3552f552cff01.

Folding hid that this move migrated bmread.c from common_sources to
editor_sources.
Normalize comments and whitespace to match D1X
Use correct array index when loading circle distance

When reading a custom robot's circle distance from a file, store into
the circle_distance[] array, rather than out beyond it.
Rename D2XMAJOR/D2XMINOR/D2XMICRO to VERSION_MAJOR/VERSION_MINOR/VERSION_MICRO
Rename D2XMAJORi/D2XMINORi/D2XMICROi 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