Docs for Panel4D/panelnd and Minor Enhancements
updated whatsnew/RELEASE
added boolean comparison methods to panel.py (didn't exist before)

all tests pass

need to update the link to dsintro-panel4d section in the whatsnew docs....

travis build is good - ready to merge
 great....fyi...there seems to be a weird bolding in RELEAST.rst (in experimental features)....
