cmText.h/c: Added cmTextIsNotEmpty()

cmText.c

   return true;
 }
 
+bool cmTextIsNotEmpty( const cmChar_t* s )
+{ return !cmTextIsEmpty(s); }
+
+
 cmChar_t* cmTextLine( cmChar_t* s, unsigned line )
 {
   assert( line>0);

cmText.h

   // Append 'n' copies of 'c' to the end of s[].
   cmChar_t* cmTextAppendChar( cmChar_t* s, cmChar_t c, unsigned n );
 
-  // Returns true if the string is all spaces.
+  // Returns true if the string is NULL or all spaces.
   bool cmTextIsEmpty( const cmChar_t* s );
+  bool cmTextIsNotEmpty( const cmChar_t* s );
 
   // Returns NULL if string contains fewer than lineIdx lines.
   // Note: first line == 1.