JASCIS-87: UngriddedDataList knows how to save data to a file; also it's coords method no longer tries to support different coordinates for different variables (assumes they're all on the same grid). Fixed bug in subset and added test for it.
JASCIS-87: Parser now splits variables on commas when and only when argument is subset (other commands remain unchanged). Added integration tests for subsetting (incl. multiple variables).
Refactoring tests; move test files back to original location (can't move them on Jenkins)