Readme.md, Contribution.md, .gitignore

#### Can't be merged in like this!
Contribution.md:
 * we should create a docs git for sphinx first( didn't want to do without asking )
 * should we mention tests at all? there are sth. like no core test cases...
 * should we setup travis-ci to check PR's?
 * do we follow any named coding standard?

Readme.md:
 * is there any mailing list, we want to link to?
 * should we mention DIY?