fixing plotting.show() and .save() to accept a plot object as an argument
fix #990
Merge pull request #993 from ContinuumIO/daylight

fix #990
Various improvements to interactive example test script.
simplify mapper directory layout
remove old unused have_new_mapper_state cruft
Merge pull request #995 from ContinuumIO/examples_test_script

Various improvements to example widget testing script
shorten/simplify screen range names
decouple axis and grids
remove need for location parameter to axes
merge master
adjust mpl.py to use new changes
some test fixups
show with no obj should show the whole docuemtn
Merge pull request #997 from ContinuumIO/bugfix/broken_doc_save

show with no obj should show the whole document
Merge branch 'master' into feature/gridaxes
remove old parameter from test
communicate mapper type
improve readability
Merge pull request #996 from ContinuumIO/feature/gridaxes

grid and axes improvements