Merge dev -> master: New branching model

We've recently changed some important stuff in lunkwill's code, such as using cmake, I thaught
this would be a good moment to introduce the new development/branching model. The single and completely
detached commit in the master branch was inconvenient (and distorted also the stats on GitHub.)

New branching model:
 - Develop lunkwill in dev
 - Frequently merge dev into cov for code analysis
 - Merge stable releases from dev into master
 - Create an -as tag for every release
 - Bug fixes can be cherry-picked
 - However, keep git usage as simple as possible, so repo won't break...