added qse_awk_rtx_pushrcb() and qse_awk_rtx_poprcb().

deleted qse_awk_rtx_setrcb() and qse_awk_rtx_getrcb().
added 'close' to qse_awk_rcb_t
added builtin functions 'setenc' and 'unsetenc' to awk/std.c
added qse_getcmgrbyname()
added builtin functions 'setenc' and 'unsetenc' to awk/StdAwk.cpp

qse/lib/awk/Awk.cpp

@@ -1510,7 +1510,7 @@ int Awk::getGlobal (int id, Value& v)
 
 int Awk::addFunction (
 	const char_t* name, size_t minArgs, size_t maxArgs, 
-	FunctionHandler handler) 
+	FunctionHandler handler, int validOpts) 
 {
 	QSE_ASSERT (awk != QSE_NULL);
 
@@ -1529,7 +1529,7 @@ int Awk::addFunction (
 
 	void* p = qse_awk_addfnc (
 		awk, name, nameLen,
-		0, minArgs, maxArgs,
+		validOpts, minArgs, maxArgs,
 #ifdef PASS_BY_REFERENCE
 		QSE_T("R"), // pass all arguments by reference
 #else