integration of sympyprt extension into sympy Part 1
fontsize fix

Signed-off-by: Thomas Hisch <t.hisch@gmail.com>
temporary fix for display_formatter problems
Added is_literal, modified literal_symbol
Added tests
Handled AttributeError
Merge pull request #1865 from srjoglekar246/literal

Added is_literal, modified literal_symbol
Added rank() to matrices

Gives the rank of a matrix via rref.
Add Benjamin Fishbein to AUTHORS/aboutus. Welcome to SymPy!
Merge pull request #1776 from thisch/sympyprt

Integration of Sympyprt extension from IPyXt into SymPy

This PR integrates the sympyprt extension for prettyprinting sympy expressions in IPython (notebook/qtconsole) into SymPy.
Merge pull request #1831 from jrioux/relational

Refactor Relational to avoid long hanging evaluations.

This fixes the underlying issue from the slow hydrogen.py example file: Relational should try not to do more evaluation than it needs to.