new GroupStyles

[mkutmon]

With GPML2017 we will define a set of new groupStyles and PV needs to be updated.

• default groupStyle: Group (no visual representation - as "Group" is implemented at the moment)
• Complex (no change to GPML2013a)
• Pathway (no change to GPML2013a)
• Analogs (protein families - current visualization style "None")
• Paralogs (pair of genes that derives from the same ancestral gene - new visualization style needed)

Current groupStyle "None" will be removed - all groups annotated with "None" will need to be converted to "Group" (manual checking needed to know which groupStyle should be used)

[DeniseSl22]

@mkutmon and @finterly : please also add the visualisation of all group styles as graphical elements (for creating legends very useful). For example, I can't create a octagon in the graphical elements (which I could use to draw a complex in a legend.