Build 6171
SVN-
Move duke3d and engine directory definitions to their proper spots, as they no longer need early definition after the great repository rearrangement.
SVN handles and Git names are merged into one person.
Move duke3d and engine directory definitions to their proper spots, as they no longer need early definition after the great repository rearrangement.
Factor out common uses of COMMONFLAGS, COMPILERFLAGS, and LINKERFLAGS into COMPILER_* and LINKER.
Collateral changes: Engine objects now use COMPILER_CXX instead of CXX, BUILD_SETTINGS_LINKER now includes GUI_LIBS, and the Build tools now use LINK_STATUS and result instead of ONESTEP.
Use the override keyword when implicitly disabling Polymer and libvpx when USE_OPENGL=0.
Remove {eduke32,mapster32}.memmap files on clean/veryclean targets
(bioman request).
remove ebacktrace1.dll as dependency to eduke32 and mapster32 and
add it to the 'all' target instead source/midi.c: eliminate one 'variable set but not used' warning