rowcache: delete socket file before and after memcache
rowcache: fix race condition between Open, Close & Put
planbuilder: compute table name first.

Setting the table name in the plan upfront gives us
more info about the query, which is useful for
blacklisting, etc.
Merge branch 'master' into vtocc
tabletserver: refactor transaction pool
Refactored keyrange.py and added documentation.
small linter improvements.
Fix for test breakage.
Merge branch 'master' of github.com:youtube/vitess
Fix issues in vtgate test.
Use shard '80-' to expose problems better.
Merge branch 'liguo'

Conflicts:
	test/vtgatev2_test.py
Fix vtrouting.py
Disable the problematic testcase in vtgate test
Voltron: Last reference removed.

Voltron was Vitess's original project name, and this was
the last reference of that name. Long live!
ActiveTxPool -> TxPool
rowcache: concurrentize delayed spot-checking

If a spot check fails, the rowcache sleeps for 10 seconds
and rechecks the data. This is to accommodate race conditions
that inherently exist between rowcache and database.
Such sleeps increase query execution time. With this CL,
the recheck is launched as a separate goroutine using the
new Launch service of QueryEngine which will ensure that
it won't be closed until such functions have completed.
tabletserver: add panic failsafe for tasks
Move Docker examples to top-level examples dir.
Add Dockerfile for vitess/root image.
First pass at Kubernetes support.