[CMake] msvc postfix conventions

[Brandon J. Van Every]

I'm trying to decide reasonable defaults for the various _POSTFIX 
variables under msvc.  My guesses:
DEBUG_POSTFIX "d"
RELEASE_POSTFIX ""
MINSIZEREL_POSTFIX "?"
RELWITHDEBINFO_POSTFIX "?"

The conventions are eluding my Google searches.  For all I know there 
may not be many conventions, as keeping debug and release builds in 
different directories is a common practice.

I have often seen "s" used for static builds. 

The msvc libraries such as msvcrt.lib have some conventions:
"t" = multithreaded, dynamic link
"mt" = multithreaded, static link
"p" = Standard C++ Library

Another question is when combining these 1-or-2-letter postfixes, is if 
they are combined in any particular order.


Cheers,
Brandon Van Every