ignore ncrunch and Visual Studio 2015 files
change InstallModel to be based on lib folders instead of groups

Until now it creates both, lib folders and framework groups. Removing groups will be the next step.
changed ProjectFile to use the new LibFolder structure
no more groups
Fix couple of unittests
Fix couple of unittests
Formatting the new PlatformMatching
Put PlatformMatching into separate file
use sprintf
Extract maxPenalty
Try to simplify penalty calculation
don't create empty <Choose /> elements
Adding tests from https://github.com/christianlang/PaketExperiments/blob/master/PaketExperiments.Test/Tests.fs
Fixing PenaltySpecs
cleanup
Fix install of tools folder
Put parens around the conditions
Use BlackList again
AddFrameworkAssemblyReferences again
If the fullframework is used we don't need to check FrameworkVersion