* Add common csproj/vcxproj settings to Directory.Build.props
* Set TreatWarningsAsErrors to true for all c# projects
* Minor fixes in unit test projects where Analyzers where not enabled before
* Clean up Directory.Build.props
* Remove properties from ImageResizer csprojs files
* Made Plugin Folder Unit tests. Fixes '>' not recursive searching (with max). Added that paths with an UnauthorizedAccessException are ignored. Added expanding enviroment search.
* Fixed some merging errors
* Added feedback from review
* Made the change that ryanbodrug-microsoft suggested
* Stupid merge request... fixed
Co-authored-by: p-storm <paul.de.man@gmail.com>