Include ()'s in latex conversion of Implies
additional test of latex Implies grouping
fix sign to recognize sqrt with negative arg
watch for sign change from I in sign()
simplify sign code, watch for recursion
add sign.is_(nonnegative|nonpositive)
Change Kane and Lagrange attributes

- KanesMethod has q and u as full attributes
- LagrangesMethod has q as a full attribute
- KanesMethod now stores forcelist and bodylist as attributes
Refactor processing of inequalities with oo [1/9]

fixes #7775
Refactor processing of inequalities with oo [2/9]

If we don't know the boundedness: _eval_is_positive/negative should
return None.

fixes #7798
fixes #7841
Refactor processing of inequalities with oo [3/9]

fix tests in test_sets.py
Refactor processing of inequalities with oo [4/9]

fix wester's tests
Refactor processing of inequalities with oo [5/9]

fix tests for inequalities.py
Refactor processing of inequalities with oo [6/9]

More tests fixed
Refactor processing of inequalities with oo [7/9]

Add import for oo
Refactor processing of inequalities with oo [8/9]

Fix physics/quantum tests due to simple bug
in Expr._eval_interval (check for NegativeInfinity singleton)

(Thanks to Aaron Meurer for idea)
Refactor processing of inequalities with oo [9/9]

Fix doctests in delta.py
Deprecate set.is_real property, use set.is_subset(Reals) instead

fixes #6212
Merge pull request #7861 from skirpichev/oo-ineq

Refactor processing of inequalities with oo
Improve Mul._eval_is_rational: add check for zero

fixes #8008
minor docstring edit [skip ci]