added prov storage for port and data mappings
switched all methods to take wf.Data objects.  runner checks server connection before running
added table schema transformations
minor reformatting
add new files
add new files
add schema transformation test
added support for date types.  fixed a number of bugs.
updated library
fixed data cloning so it clones the table
added wrapped facetting, auto-pick xaxis ticks, and cdf statistic
refactored shorthand layer.  accepts list of stats
fixed tests. all tests pass
adde groupby xforms
fixed schema inference
adde groupby test
fixed schema bug in groupby