ENH: Moved kwsys_ns and kwsysEXPORT macros to Configure.h in the case of building a kwsys source file.  This allows more than one header to be included in a kwsys source file without redefining the macros.

ENH: Do kwsys testing as part of cmake testing, command line arguments are not experimental and add simple test for systemtools

ENH: Added kwsysProcess_Disown an kwsysProcess_Option_Detach to allow detached processes to be created.  Currently implemented only on UNIX.

ERR: Avoiding namespace pollution: kw_sys -> kwsys_ns.  Also undefining the macro at the correct time.

ERR: On Borland preprocessor goes into recursion which adds some weid spaces in the include name. This fixes it

ENH: Added GetExceptionString method to provide an error description when GetState returns Exception.

ENH: Added SetPipeShared method to allow stdout and stderr pipes to be shared with the parent process.

ENH: Added SetPipeFile method to allow the process pipeline stdin, stdout, and stderr to be redirected from/to files.

ENH: Removed pipe selection argument from WaitForData method in kwsysProcess.  This greatly simplifies its use.

ERR: Reduced requirements on preprocessor for export macro due to limitations of Mac preprocessor.  The preprocessor can be fixed by using -no-cpp-precomp, but we don't want to require that option for every source file that includes our headers.

ENH: Added documentation to interface.  Finished process exit code interpretation implementation prototype.