Merge pull request #26 from ramon-astudillo/student

First version of future student branch
Merge pull request #27 from ramon-astudillo/student

Corrected github URLs, added undo mode in solve.py
Merge pull request #28 from ramon-astudillo/student

Solved typos in README
Merge remote-tracking branch 'upstream/student' into student
Moved instalation checker from master to student branch