Copy constructor bugfix release

This release fixes the broken copy-constructor assignment pointed out by @lukasberbuer and a lot of smaller fixes by many others in particular for the cmake file but also missing default constructors so that iir library instances can be re-assigned without the need of new/delete which is the way forward. There is a new unit test which also tests the copy-constructor.
There are now options to disable exceptions, the unit tests and the demo programs.