cleanup debugger code
replace DBG_DBG macro by standard NDEBUG
rename files to use dbgw... prefix if contain code for UI (not used by debug core)
use dbgdata.h for all global data (used by debug core)
minimize global declaration in source code, use header files as much as possible
rename DIP priority macros DP_..... to more readable DIP_PRIOR_... to prevent collision with OS/2 Presentation Manager DP_... macros