strange commit for strange rebase
Merge branch 'master' of https://github.com/kontur-edu/uLearn

Conflicts:
	src/courses/BasicProgramming/Slides/U02_Mistakes/S01-MissedUsings.cs
	src/uLearn.Web/Scripts/slide.js
	src/uLearn.Web/Views/Course/_SlideNavigation.cshtml
merge branch