Better text decoding.

The HTTPClient also strips forgein characaters now!
Whoops again!
Yeah. Last 2 commits were a failure. Whoops..
Performance improvements!
Added MagisterMessage.TrySend() and...

code cleanUp and a bugfix in the StudyGuide class
Some optimizations :)
I didn't like something I did yesterday..
Fixed new line in messages.

I'm pushing way too many commits I think.
Performance and more stuff.
Let's do it even smarter.
Stuff I don't remember
Some bugfixes.
Added the enum HomeworkType
Made HTTPClient nicer.
Added method to quickly send a message.
Centralized Attachment[] to List conversion.
Just some little things.
Centralized String to DateTime conversion.
This is like the useless commit ever
Made MagisterPerson comparable