Multiple Level Selection Information, Updater and Solver Flickering

Code was cleaned to handle selections at multiple levels (like when you click on a shape, the internals of NaroCAD will know that you selected both an extrude and it's face with it's index 3). Previously this code was handled manually, but right now there is logic that a tool can get all information about selection. This also solves an issue that in the last nightly build(s) that clicking on a line will make the floating toolbar to not appear (because it expected at least a face-based shape, if not a volume based one).
This code is also aware of the current selection mode the user picks.
The updater will be less intrusive by downloading in background the next version and will apply next time on startup the downloaded install package. When the background downloaded is finished, it will show to you just a notification icon.
Of course if you don't updating at all, you still have the option to not download the new versions if you will go to Options page.
A lot of flickering when updating solver points/lines was removed. This may solve some slow performance issues. Also the solver previously did display just one point/line or whatever appear as first shape to be drawn. Right now all shapes are drawn (like if you have a Point match and a Edge Continuation match), but even all shapes are displayed, the rules apply in the old priority order (like: Point match is picked before Edge Continuation match).