FOSS Lectio improvements von Drillenissen

The extension is a collection of simple improvements to the lection app.

Features include:
- Opgave skjuler (viser kun opgaver der mangler at blive aflevere, med mindre man tjekker den af)
- Wide lectio (lectio fylder hele skermen)
- Lectio Colors (farver på skemaet og andre steder :00)

PR's are welcome, for feature requests open an issue
https://github.com/logicguy1/FOSS-Lectio-improvements