Add option to store to parittion data
Move column name resolution to non-internal function
Add shuffle operator before store
Move attribute ref resolution to top-level function
Test of user-directed partition operator
Add dot files to gitignore
Change a myrial example to use explicit partitioning
Do not sort the shuffle columns
Merge pull request #196 from uwescience/andrew_partition_on_store

Support repartitioning data from within Myrial