Add explicit stack size limit in python turmit

gte/turmit.py

         #  @note This limit is handled by @ref rpnlib.RpnOp()
         self._signed_int = True
 
+        self._stack_max = 0xFFF
+
         if 'max_int' in kwargs:
             v = kwargs['max_int']
             if v < 1:
         '''
 	    
         stksz = len(self._stack)
-        new_sz %= 0xFFF
+        new_sz %= self._stack_max
         if new_sz < 2:
             new_sz = 2
         if new_sz > stksz: