cmLib.c:cmLibInitialize() now checks for empty as well as NULL library path

before scanning for libraries.

cmLib.c

 #include "cmCtx.h"
 #include "cmMem.h"
 #include "cmMallocDebug.h"
+#include "cmLinkedHeap.h"
 #include "cmFileSys.h"
 
 #include "cmLib.h"
+#include "cmText.h"
 
-#ifdef OS_LINUX
+#ifndef NDEF
 
 #include <dlfcn.h>
 
 
   hp->h = p;
 
-  if( dirStr != NULL )
+  if( cmTextIsNotEmpty(dirStr) )
     if((rc = cmLibScan(*hp,dirStr)) != kOkLibRC )
       hp->h = NULL;