Removed use of mbrtowc, wcrtomb, and mbsinit. Many platforms

didn't support them and the emulated versions were just as good
except for a performance problem with excessive locking and
unlocking of a mutex.  So this also changes IArchString to
provide string rather than character conversion so we can lock
the mutex once per string rather than once per character.

lib/arch/CArchStringUnix.cpp

@@ -15,22 +15,11 @@
 #include "CArchStringUnix.h"
 #include <stdio.h>
 
-#include "CMultibyte.cpp"
-
 //
 // CArchStringUnix
 //
 
-CArchStringUnix::CArchStringUnix()
-{
-	initMB();
-}
-
-CArchStringUnix::~CArchStringUnix()
-{
-	cleanMB();
-}
-
+#include "CMultibyte.cpp"
 #include "vsnprintf.cpp"
 
 IArchString::EWideCharEncoding