Added string2.tut
Added string3.tut
Added except1.tut (including rewrite of the question)
Added except2.tut (including rewrite of question)
Changed all decoding to utf8 (from ascii)

All encoding is still ascii, as we control that input completely

Resolves #36
Removed deprecated calls
Integrating the new online interface with the application.

* Renamed LoginManager to SessionManager
* Replaced get_mpt27 with get_mpt34
* Removed some of the existing login/logout stuff (TODO: still need to remove other bits of it which are no longer used)
* Removed TutorialInterface._send_data, replaced calls with SessionManager.get/post

A functional change is that when not logged in, instead of "You don't appear to be connected" messages, users get prompted to log in.
Merge branch 'sso' of github.com:CSSE1001/MyPyTutor into sso

# By sapi
# Via sapi
* 'sso' of github.com:CSSE1001/MyPyTutor:
  Changed all decoding to utf8 (from ascii)

Conflicts:
	code/tutorlib/online.py
Merge branch 'master' into sso

Conflicts:
	code/tutorlib/TutorialInterface.py
Merge branch 'sso' into refactor

Conflicts:
	code/tutorlib/TutorialApp.py
	code/tutorlib/TutorialInterface.py

Moved sso code from TutorialInterface.py to its new home in web_api.py

Did not update code in TutorialApp.py (notably the zipfile stuff), as
that is not in the current version of gui/app/app.py
It will need to be re-added at a later date, based on the information in
sso prior to this commit and the old logic.

See discussion in #7