PEP-8, complete coverage for filesettings, removed unused code
Get both files and folders
Almost working courses tab

Also add icons and some auxiliary script to understand tableview and
model.
A better resizable window
Change code to use new interface
Stdout goes to "status" textbox
__init__.py re-inserted and renamed polibeepsync to common

Import statements have been rewritten to accomodate file name change.
Ok button hides window
Default text for login information label
Add functionality to GUI

* implemented insertRows and removeRows to update the view when new
courses are available or when some should be removed
* load username, password, courses list from "data" file
* testlogin() ensures that the user is logged
* refreshcourses() synces the local state of data with the remote
website
* syncfiles() should be able to download files to local directories (not
tested)
Function to save a folder recursively +  tweaks

The function is not tested yet; other tweaks are

* helper function to get the modification date for a local file
* new courses created default to sync=False
* updated docstring for logout()
Change in filesettings defaults and updated unit tests
New class style for common classes
Refactoring

Moved code to MainWindow definition; use threads for login and courses
synchronization
Bugfix: refresh courses thread now exits when done
Restore default sys.stdout
Use myStream_message function to add text to "status"
Remove old comments from LoginThread
Connect ok/error signals to both login status and status textbox
BUGFIX: correct behaviour when refreshing courses

Before this fix, the "ok signal" from loginthread is not disconnected
from do_refreshcourses; therefore, the next time the user presses "try
login credentials", the function do_refreshcourses gets called.

The function do_refreshcourses should be called only when the ok signal
is emitted from the loginthread started by refreshcourses.