Lofar-h5plot

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).

**Updates**
* Flagged slots are now plotted as red vertical lines in 1D plots and white squares in 2D plots.
* UI has minimize, maximize and close buttons on plots.
* Plots will now scale with window size.

**Bugfixes**
* Fix waterfall plots not having the correct orientation.
* Fix waterfall plots not handling scalar quantities correctly.

**Updates**
* Added waterfall plot functionality (2D time-frequency plots) for amplitude, phase and polalign.

**Bugfixes**
* Properly select values for directions other than index 0.

**Bugfixes**
* Fix an issue with TEC plotting

**Bugfixes**
* Fixed small string decoding issue.