Added the possibility to do a concentric progression (the view has multiple circles of progression).
Need to add documentation about this, clean the code and stuff.
Finally fixed an issue about outline drawing for some values
Added an option to always draw the outline.
Need to clean the code and document that better.
Added the possibility to assign a gap between layers of concentric circles.
There still is a bug when using concentric steps and normal steps for some values.
Change some floats into CGFloats and added a few lines of documentation