Fix test_printing.py
Raise NotImplementedError if left/right_open is not S.true/false
Merge pull request #2907 from skirpichev/imageset-uneval

imageset() improvements
matadd/matmul: fix doc and unittests

Signed-off-by: Thomas Hisch <thomas.hisch@ims.co.at>
Merge pull request #17 from thisch/mrocklin-matexpr-sympify

matadd/matmull fix unit and doctests
Workaround Dummy's printing in Subs constructor (fixes #7068)
Add test for issue 7068
added _eval_power to IdentityOperator to avoid unevaluated expressions like I**2
fixed the min in dup_roots_upper_bound
added a line I had missed to copy
Merge pull request #2987 from jcrist/master

Added support for kwarg "use_array" in lambdify (fixes  #2931)
Deprecated method kwarg in LagrangesMethod.rhs

Added deprecation warning for method kwarg for LagrangesMethod.rhs.
Changed mat_inv_mul to _mat_inv_mul.
fix Dummy.sort_key and use it in expr.sort_key

Also, catch any new Numbers that are generated by the rebuilding
of terms in Mul.flatten. Rather than check them at each step of
the way, just handle them once when done traversing the args.
Merge pull request #2984 from Tempel/number_ineq_STrue

Inequalities: return BooleanAtoms instead of bools.
replaced tabs by spaces
"beautified" comments
more "beautification"; hope last commit
comments became green
Update Rajat Aggarwal's name in AUTHORS/aboutus/.mailmap
Added DFT matrix