Include documentation and example files in built RPM

Seeing that the module will be installed on many plattforms in form of an
RPM, it is wise to have the documentation files and also the example
agent and its files included.
Fix ChangeLog generation for the case when we're on a tag

The mechanism erroneously tried to generate a changelog "between vX.Y and vX.Y" when
we're on that very tag.
Add increment method to asntypes COUNTER and COUNTER64
Formatting for consistent code style
Update README to reflect commit activity

This is more and more getting fun :-)