Add temp. files to gitignore
Added trg_cong class
Added new code to make_triangles_congruent
Merge branch 'master' into doc

Comments were removed from master, and I am
going to make new comments and docstrings.
Added Docstrings
Merge branch 'congruency'

Conflicts:
	prove.py
Removed sets and replace by lists.

WHY, WHY did i use sets?