Actually forwarding user and password through vtdb

We haven't been using SALS since 2013/09/19... and vtdb test just
revealed it since we back-ported google3 code.
Updating this test.
Test for illegal tablet type transitions.
Small refactor of tests for mysqlctl.
Configure vtgate -> vttablet protocol in env.
Refactoring rowcache_invalidator.py test.

No unnecessary sleep, simpler init code, using vtgate instead
of zkocc, faster run, ... now takes less than 20s to run.
Removing couple unused imports.
Small cleanup in this file.
Deleting these modules as this is unused code and that direction is deprecated.
Pruned the deprecated variables from replica.cnf.
Module and test to compute the task map and query where clauses for streaming queries.
Modified keyrange code and test to be aware of keyspace_id type.
Changed the constants for KeyspaceIdType to same as go code.
Changes to KeyspaceIdType var names to make it consistent with go code.
Fixing this test after error messages changed.
Using dynamic port for vtworker instead of 8085.
Replacing a few raise with self.fail in tests.
Actually forwarding user and password through vtdb

We haven't been using SALS since 2013/09/19... and vtdb test just
revealed it since we back-ported google3 code.
Updating this test.
Merge branch 'test-for-state-change'

Conflicts:
	test/reparent.py