remove no-op synchronisation in executeCallbacksLoop

There's a lot of ceremony there, but if you look hard enough, you'll see
that there really isn't much guaranteed by doing so.
StopSlaveMinimum now actually stops the slave.

Instead of just waiting for a minimum position.
Adding extra headers so compiler has them.
Adding a check to ShardMultiRestore.
Raise a compile error for implicit declarations in CGO.
Fixing error message.
Merge branch 'master' of github.com:youtube/vitess
Add "go vet" as a presubmit and use goimports instead of gofmt.
Fix all govet issues in preparation for govet presubmit.
Add an integration test for VTGate V2
One extra test case.
Stopping and restarting replication around multirestore.
Merge branch 'master' of github.com:youtube/vitess
Merge branch 'master' of https://github.com/youtube/vitess
Include vtgatev2 test in integration test
Merge branch 'rowcache'
Merge pull request #71 from plobsing/no-sync

remove no-op synchronisation in executeCallbacksLoop
Reducing log in primecache.
Merge branch 'master' of github.com:youtube/vitess
Adding a flag to delay rebuilding serving graph.

Useful for doing one cell at a time.