Lofar-h5plot

**Updates**
* Add option to plot all stations in case of waterfall plots.

**Bugfixes**
* Disable diffs when plotting weights.
* Don't keep the main window on top.
* Wrap diffs of phase quantities properly (fixes 22).
* Remove unused text that clashed with single-polarisation h5parms.

**Updates**
* Add option to plot weights.
* Add option to plot the forward difference along time and frequency axes.
* Add option to plot the XX-YY polarisation difference.
* Add a scrollbar for easier navigation.
* Plots now grow with window size.

**Bugfixes**
* Don't set flagged solutions to NaN (confusing for when solutions are actually NaN).

**Updates**
* Irregular h5parms with gaps between data are now padded when plotting waterfall plots. Irregularity is determined based on the first two time and frequency slots.
* Fixed a bug where switching between polarisation cleared the plot title.

**Updates**
* Plots adapt to the size of the window

Main feature update in this release is the addition of antenna iteration. This allows one to browse the various antennas at the given time or frequency slot that is being displayed.

**Updates**
* Add help message
* Added some potentially exotic cases to reference station use
* Added iteration over antennas in plot windows
* Disable anti-aliasing for waterfall plots

**Bugfixes**
* Fixed phases not being referenced properly for phase soltab without polarization and direction axis.
* Fixed crash when attempting waterfall plot for unsupported solution types
* Fixed waterfall plot for polalign soltabs
* Fixed waterfall plots for Nx1 or 1xN arrays

**Bugfixes**
* Fix weights not being passed for TEC like solutions (i.e. no frequency axis).