Improve error messages. More detail required.
Add notes about Inheritance
Clean up Inheritance unit test
Remove opEnumerate

This function was used to transition from Atlas-C++ 0.4 to 0.6.
It is no longer used at all, as operations have an integer type.
Remove opInstall

The only purpose was to support opEnumerate
Add another note
Remove unused include
Remove unused include
Stop using OpNo typedef
Stop using OpNo here too
Remove typedefs for OpNo