hard to flag CABB data

[JamieStevens]

Currently there is only one reliable method of flagging CABB data, and that is to manually specify flagging regions using uvflag. This does not necessarily mean that comprehensive flagging is impossible, but rather that it takes much longer than it needs to.

To improve the efficiency of flagging, it would be desirable to:

• improve blflag:

+ allow blflag to replicate most/all of what uvplt can do, in terms of axes

+ allow blflag to display data that has not been averaged over frequency

+ show all Stokes parameters in blflag, and leave points out of blflag plots only when all Stokes parameters are flagged (currently, for example, if XX is flagged, blflag will not display the unflagged YY value for the same visibility)

• make tvflag work with 24-bit displays; now that all data has thousands of channels, flagging bad channel ranges can be quite tedious using only uvflag

[MarkWieringa]

blflag now has a noqav option.

[MarkWieringa]

a nofqav option that is. Allowing all channels to appear on the plot.

[MarkWieringa]

Added channel as an options for axis.

Use option=scalar to see all rfi, multiple polarizations are averaged which may mask rfi in vector averages.

[MarkWieringa]

blflag flags all polarization when one is flagged. If previous flagging has been applied use uvpflag with options=or to flag all stokes when one is flagged. Jamie has written pgflag as a tvflag replacement. This addresses most of the issues.