Show IF and scan number of spectrum on flagplotter (from CAS-5140)

[Kana Sugimoto]

Reporter: ALMA-CSV team (Shinya Komugi)

the task sdflag will benefit greatly from some improvements, mostly owing to the fact that single dish data has many rows compared to the interferometric data. Below are few that are important for efficient data reduction.

1) <snip>

2) when using interactive=T, the plots should show what IF number and Scan is shown, instead of just the rownumber in the data table.