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/http/XHTTP.h

@@ -62,6 +62,7 @@ private:
 	CString				m_reason;
 };
 
+//! HTTP exception indicating an unsupported method
 class XHTTPAllow : public XHTTP {
 public:
 	/*!