Sortable Library contents

[micheljansen]

Sort by type etc.

[DennisReidsma]

Or maybe also by "group" like in the previous version (where each processor had a name and a group name, like "Dennis' processors", or "edge detectors", or "custom processors for project XX"

[micheljansen]

There are currently not enough processors to justify the amount of time it would need to implement this. Processors are now sorted by their name. In the future, this could easily be extended by modifying LibraryWidget.cpp.