[CMake] Supported configurations with Visual Studio builds

[Sylvain Benner]

> What about the debug/optimized flags for TARGET_LINK_LIBARIES()?  Do
> these work right now by taking advantage of the fact that Debug,
> Release, MinSizeRel, and RelWithDebInfo are hardcoded?
>
>
> Also, judging by code in cmLocalVisualStudio7Generator.cxx any custom
> build solutions that you would added would probably only work as release
> libraries:
>
>     if(strcmp(configName, "Debug") == 0
>        || strcmp(configName, "RelWithDebInfo") == 0)
>       {
>       fout << "\t\t\t\tGenerateDebugInformation=\"TRUE\"\n";
>       }
>   
I second this.

We had to "upgrade" the cmTarget sources to add the new configuration 
type and then use the LINK_LIBRARIES command correctly. Actually this is 
the only thing that prevent us from defining new configuration types 
without hardcoding anything, configuration types merely never change so 
this is not an annoying thing for us, but this is a big blocking issue 
if you want to add this feature in a release.

For the second thing, we added new entires in the flag map of the 
generator :

cmVS7FlagTable cmLocalVisualStudio7GeneratorMPLinkerFlagTable[] =

   {"GenerateDebugInformation",   "DEBUG",     "Generate Debug 
Info",       "TRUE"},
   {"GenerateDebugInformation",   "NODEBUG",   "Don't Generate Debug 
Info", "FALSE"},

--Sylvain