includes imaging option to split channels when gridding uv plane (now default)
added new functions by David Kaplan. self.l0/m0 now tracks phase center shift for each int.
optionally imports ephem and pywcs to convert to/from ra/dec.
fully removed channel dependence of uvw for now.
fixed dmtrack fail for too-large a track
added multi-pol miriad reading. mirrors ms syntax
fixes to integration-based searches to used masked_array. also changed iteration range for make_bisp
last version of the original merged with is from 20130408. introduced a lot of printing in tracksub and make_bispectra. found that the original version from 20130408 does not fully disregard flagged data, thus procedures introduced in tracksub to disregard flagged data (they should be uncommented)
Save modified tpipe.py & tpipe_pyrap.py