Initial commit for splitting triggers into smaller tasks, then grouping them into program-level tasks that can be run in parallel
implement wordsCount by using hash function
Merge branch 'master' of github.com:DaMSL/K3-Core
simple program transformation finished, needs testing/cleanup
Merge branch 'master' of https://github.com/DaMSL/K3-Core
Merge branch 'master' of https://github.com/DaMSL/K3-Core
minor changes
Merge branch 'master' into external
Add implementation of variant dataspace
combineDS copies the dataspace so a collection can be combined with itself
Use the initialCtor to construct literals / globals

This fixes a bug where any literal would have an InMemory dataspace regardless of the annotations on the collection
give emptyCollections the right annotations
Add method definitions for the External annotation
Use record for binders (instead of tuple) in rebuildCollection
That "fix" in bf12fea actually just wrote the second argument to combine on top of the first one.  So actually append here.  And add an extra test.