path works on expressions with more than one input

Used to assume expr had join.  Now it uses inputs.  So it works on join
keywords works on class constructors

but not on carray

Conflicts:
	blaze/bcolz.py
correct imports for keywords bcolz
path exits cleanly
move binary operators up to tableexpr
Merge pull request #633 from mrocklin/minor-fixes

Minor fixes
Added search bar at the top.
Merge pull request #644 from brittainhard/doc-search

Added search bar at the top.