Merge pull request #7634 from sushant-hiray/coth-fix

Fixed value for `coth(0)`
watch for improper separation of base and exp in powsimp

e.g. sqrt(x**a) should not be split as x**a, 1/2 otherwise
it will rejoin as x**(a/2) later -- this is noted with an
inline comment.

For example, consider sqrt(exp(x)) which previously simplied
to exp(x/2). It is easy to demonstrate that these can be different:

>>> eq = sqrt(exp(x)) - exp(x/2)
>>> eq.subs(x, 3 + I).n()
-7.86610435188672 - 4.29727239280679*I
Merge remote-tracking branch 'upstream/master'
Implement __ne__() by calling __eq__()

The __ne__() operator should return "not __eq__()". Alternatively, one can copy
& paste the algorithm from __eq__() and negate the answer right before each
return. But anything else means there is a potential bug.
Merge pull request #7636 from smichr/pow

remove positive kernel handling
Fixed PropKB. Added valid and entails
Update piecewise.py

Corrected a typo.
Added tests for new classes
Merge branch 'master' of https://github.com/sympy/sympy into basicvector
Merge pull request #7647 from coder006/typo

Correct a typo in piecewise.py
Merge pull request #7645 from certik/ne

Implement __ne__() by calling __eq__()
Merge branch 'sympy'
Added Ambar Mehrotra to the AUTHORS/aboutus. Welcome to SymPy
Merge pull request #7625 from hargup/imageset_simplification

Added a few rules for imageset simplification
Incomplete doc in deutils

A line is complete in docs in _desolve in deutils. It can be more than one thing possible there. I need suggestions to complete this sentence.
Rewrite lambda as a function.  This avoids a runtime error (i.e. return
value of cached and not cached function differ)  with

SYMPY_USE_CACHE=debug py.test -x sympy/integrals/tests/test_trigonometry.py
Merge pull request #7613 from clsn/str_unicode

Handle unicode literals properly in matrices
Add deprecation warning for sympy.physics.gaussopt
Change Google code to GitHub in SymPyDecprecationWarning docstring
Add issue number(7659) in the deprecation warning