Propagate CMAKE_C_COMPILER and CMAKE_RC_COMPILER to aid workaround for "NMake Makefiles JOM" generator which requires these variables to be set for now for any non cl compiler, e.g., MinGW gcc.
Propagate CMAKE_C_COMPILER and CMAKE_RC_COMPILER to aid workaround for
"NMake Makefiles JOM" generator which requires these variables to be
set for now for any non cl compiler, e.g., MinGW gcc.

Some logic cleanup

svn path=/trunk/; revision=12385

FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot