Improve handling of PK-Sim module conversion to extension module

[rwmcintosh]

We have implemented something for warning a user when a module is converted from PK-Sim to an extension module.

The implementation just warns the user any time a building block version number is updated. This is also how we are testing for whether a module is PK-Sim or not. If any of the module building blocks does not have the same version as created in PK-Sim, then it's not a PK-Sim module.

There are a couple problems with this implementation

1. The test in version updater is very low level in the call chain and is executed during command execution. If possible, it should happen before, and allow user to cancel.
2. Not all changes to a building block render the module as extension module. Eg. if you change a building block name, it should remain a PK-Sim module.

Some analysis needs to be done to separate what commands really mean the module is extension module.