Merge branch 'release-0.2.1' into development
Defaulting to UTF-8 when reading and writing files. Closes #14.

The previous behaviour was using the system locale. If the user wants
the system to take always the default locale, they can do it through
the configuration file (see doc/samples/eyegrade.cfg).
Removed a debugging message in the GUI module.
Better checking of student lists.

Fixes #64. Fixes #54.
Update changelog and version number for release 0.2.2.
Merge branch 'release-0.2.2'