Lie algebras: Type A
liealgebras_1: some updates
liealgebras_2: Type B
Travis: don't install all the *-doc packages

This should significantly improve download time / traffic.
liealgebras_2: some updates
liealgebras_1: more fixes
Merge branch 'master' into travis

Conflicts:
	.travis.yml
Travis: fix the missing "lmroman10" problem

I followed the advice from:

http://tex.stackexchange.com/questions/652/xetex-not-working-on-ubuntu-10-04
Rewrite atan2 as arg function
Improve rewrite of atan2 in terms of arg
Test rewrite to arg
Eval conjugates of atan2 expressions
Adding some files
Adding liealgebras to setup.py
Importing PR with Jordan form reduction for matrices
All tests now pass, code clean-up
LaTeX fix in documentation of jordan_cells
Address review comments
Few modification of ntheory
Remove unnecessary ()