Implemented LaTeX support. Only colors are supported but it does already what I need.

Tested with subnetcalc and ls.
Updated README.rst.
Added first test for LaTeX output.
Added title and linkify for LaTeX.
Trying to fix https://travis-ci.org/ralphbean/ansi2html/jobs/25808505.
Fixed unicode escape problem. Fixes https://travis-ci.org/ralphbean/ansi2html/builds/26243970.
Sure % has a special meaning …
Merge pull request #48 from ypid/ansi2latex

Started to implement LaTeX support