Remove some heuristics in the e.is_Mul branch of limit()
Remove limit() heuristics for tan/cot
Cleanup e.is_Order branch in limit()
Remove e.is_Rational branch in limit()
Cleanup of e.is_Mul branch in limit()
Cleanup of e.is_Pow branch in limit()
Remove some heuristics in e.is_Add branch of limit()
A better handling of unbounded arguments in Add._eval_as_leading_term
Remove e.is_Pow branch in limit(), adopt some tests