Don't skip fusion test.
Smarter reuse of tree.
Formatting
Merge branch 'development' into feature/stencil-fusion
Merge branch 'development' into feature/stencil-fusion

Conflicts:
	hindemith/fusion/core.py
Merge branch 'master' into feature/stencil-fusion
Stencil->array_op fusion works
Merge branch 'feature/stencil-fusion' into development