Enable the build command override the .DSC file contents to enable debug output and...

Enable the build command override the .DSC file contents to enable debug output and specify which debug messages are displayed.  An example:

build  -a IA32  -a X64  -t VS2008x86  -p AppPkg/AppPkg.dsc  -b DEBUG   -D DEBUG_ENABLE_OUTPUT=TRUE   -D DEBUG_PROPERTY_MASK=0x27   -D DEBUG_PRINT_ERROR_LEVEL=0xFCF00040

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-by: Daryl McDaniel <daryl.mcdaniel@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14859 6f19259b-4bc3-4df7-8a09-765794883524