Improve RedDeer update site layout #831

As described in the task, I created additional groups
in the RedDeer site:
Runtime/API
UI
Tests/Examples
Sources
Dont open preference dialog when select method is called. Fixes #826
Performed clean-up on AbstractView (fixes #767)
Closes Secure Storage shell if opened during RepoConnectionDialogTest. Fixess #840
Fixed various delete shell in explorers (fixes #798)