Moved CPrimaryScreen and CSecondaryScreen to the lib/synergy

and the platform specific implementations to lib/platform.
Added an lib/arch method to query the platform's native wide
character encoding and changed CUnicode to use it.  All
platform dependent code is now in lib/arch, lib/platform,
and the programs under cmd.  Also added more documentation.

lib/arch/CArchStringUnix.h

@@ -19,6 +19,7 @@
 
 #define ARCH_STRING CArchStringUnix
 
+//! Unix implementation of IArchString
 class CArchStringUnix : public IArchString {
 public:
 	CArchStringUnix();
@@ -33,6 +34,8 @@ public:
 	virtual bool		isInitMBState(CArchMBState);
 	virtual int			convMBToWC(wchar_t*, const char*, int, CArchMBState);
 	virtual int			convWCToMB(char*, wchar_t, CArchMBState);
+	virtual EWideCharEncoding
+						getWideCharEncoding();
 };
 
 #endif