Fixes #7886
Added tests for ccode piecewise printing

Tests for multiple conditions, with and without assignment.
Added test for piecewise w/o assign_to
Added travis testing support for autowrap (i.e. cython and f2py).
Fixed variable naming.
Merge pull request #7865 from hargup/complement_fixes

Fix Intersection Complement simplification
Merge pull request #5 from moorepants/travis-autowrap

Added travis testing support for autowrap (cython,f2py).
Merge pull request #7885 from debugger22/ne-f

Raise NotImplementedError for unequal frequencies. Fixes #7884
Merge pull request #7878 from Tempel/7814_ellipse_symbolic_intersect

Fix #7814: Handle symbols in line-ellipse intersection.
Merge pull request #7888 from jcrist/codeprinting_tests

Added tests for ccode piecewise printing
Added returning of False for UNSAT theory.
Improved pl_true
raise error for non-pi/2 ellipse rotation
Merge pull request #10 from smichr/ellipse

raise error for non-pi ellipse rotation
Merge pull request #7614 from debugger22/ellipse-evolute

Add evolute method to calculate evolute of an ellipse
Merge pull request #7881 from jcrist/autowrap_improvements

Autowrap improvements
Remove .is_finite assumption

fixes #5393
fixes #5385
fixes #7007
Merge pull request #7891 from skirpichev/remove-is_finite

Remove .is_finite assumption
5083: make bases somewhat canonical wrt sign

There are different levels of sign extraction:

1) coefficient sign
2) extractable sign via could_extract_minus_sign
3) "           "    via signsimp

Some sort of sign simplification must be done by Pow or
else other routines cannot do theirs. e.g. if (1-x)**3 is
written as (-(x - 1))**3 by extracting a sign on the interior,
if Pow doesn't do anything then a non-Pow routine has to do the
work. This PR implements handling of the leading coeffient's sign.
added function for LaTex printing of Xor statements