Change sum() implementation multiplicity [1,1] instead of [0,1]
Merge branch 'unstable' of https://github.com/metaborg/relations into unstable
added yellow grass example model
testcases for duplicate roles, inverses and shortcuts
(duplicate shortcuts generated by desugarings errors are not showing up)
fixed duplicate shortcuts generated by desugarings errors are not showing up
+ fixed testcases that contained duplicate shortcuts by desugarings
expanded yellow grass example model
fixed yellow grass example model (tagtags are a graph not a tree, and actors are now part of events, not of all the subtypes)
yellow grass example updated
improve hover behaviour in editor
improve hover behaviour in editor (for reference and definition strings)
improve hover behaviour in editor (for toplevel ast nodes)
yellow grass example updated: made events relations
up version number to 0.2.2 (hover message fixes, shortcut error fix, added testcases)
Merge pull request #6 from metaborg/unstable

v0.2.2