SSR plugin: improvements

Due to great number of panels in SSR plugin (first drawings took 5 pages of paper on notebook), I've decided to put each panel in separate class (extension of JPanel). Also, I've re-used code from GMTIGenerator to get the table to enter lat/lon coordinates. Right now I have implemented all Requester ID and all GeoArea* panels.

It's all getting more and more in shape. Yikes! :-)