include a test
more useful pdf dot for this stuff
Merge branch 'bmyerz-matrix-multiply' into bmyerz-join-hacking
join swap sql test
test switching
proper join swapping, but still buggy selects
generalize the reindexing of the condition
clancommon.SwapJoinSides: fixes

The emitters were wrong. Also, make the emitters copy the current
variable names.
fix the emitters
Merge branch 'bmyerz/join-hacking' of github.com:uwescience/raco into bmyerz/join-hacking

Conflicts:
	raco/language/clangcommon.py
fix a inconsistency in the sql test for join swap
forgot to refactor EMIT_FILE properly
one_join_switch test unneeded
enhance assertion for hashjoin condition
privatize get_physical_plan_for
add optional 'title' arg to dot files using kwargs
enable physical plan changes with kwargs
move swapjoin sides to Rules
create dots for all optimization steps for RACO_OPTIMIZER_GRAPHS
terminal coloring utility