Don't use an unnecessary closure in read_records().

--BRJ
Allow parameter 'latest' to load latest data

Had to do some reworking of DataNamer.  Hopefully doesn't break any
other usage.

--CAR
label -> axisLabel refactor from a while back

--CAR
Attempt to generalize state tomography for multi-channel data

--CAR and TAO
Nicer Latex printing on cavity power plot

--BRJ presumably
Merge branch 'develop' of github.com:BBN-Q/Qlab into develop