Login & Logout in Tests

Signed-off-by: René Meye <rene@meye.md>
Nicer Welcome Message on HowTo Page

Signed-off-by: René Meye <rene@meye.md>
Plots in Solutions

this fixes #38 #41 #50

Signed-off-by: René Meye <rene@meye.md>
Added Question overview

This and the following fixes #52

Signed-off-by: René Meye <rene@meye.md>
Added Solution overview

Signed-off-by: René Meye <rene@meye.md>
Made Mathjax and Redcarpet(Markdown) compatible

this fixes #63
you have to use "`$" and "$`" if there are problems

Signed-off-by: René Meye <rene@meye.md>