Move debug() decorator out of gruntz.py (issue 2163)
Move maketree() and tree() functions out of the module namespace
Rename global variables for debug_decorator()
Adopt docstrings for debug_decorator()
Fix commented out test after pr #2318
Fixing problems to merge with master
Min/Max is_real if arguments are_real
add transform method for sets
Fixing more errors
Changing import
improve docstring of ``Set.transform``
Merge pull request #2297 from meclark256/liealgebras_3

Liealgebras 3
add examples and see also header to Set.transform
Merge pull request #2321 from skirpichev/2163-gruntz-debug

Move debug() decorator out of gruntz.py (issue 2163)
Merge pull request #2340 from mrocklin/transform_set

Transform set
Fixing merge conflict