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
Add testing for pytables light dd
Implement pytables ligth
Implement np.ndarray <- tables.Table for time64col
Flesh out testing
Return if there are no time64 fields
Test from ndarray to pytables
Sort types function
First pass
Move to data
New test_pytables for data
Infer using individual columns
Move data related tests to blaze/data/tests/test_pytables.py
Debugging
Remove unused imports
sort_dtype_items is more useful than forcing a dtype