Improve checks for invalid values

We determine address_masks using log/ln2, which cannot accept 0.
Therefore we don't support address spaces with a maximum_address of 0.
This can affect registry hives, so we've added a check in registry hives
to prevent creating layers with invalid maximum_addresses.

volatility/framework/exceptions.py

@@ -52,3 +52,7 @@ class SymbolSpaceError(VolatilityException):
 
 class LayerException(VolatilityException):
     """Thrown when an error occurs dealing with memory and layers"""
+
+
+class StructureException(VolatilityException):
+    """Thrown when an error occurs dealing with an expected structure type"""