Activate Grunt rev task

- Prepends js and css file names with md5 of
contents so web browsers don't load cached files
when the contents has changed.
Add no-cache headers on Ajax GET calls.

- Fixes IE 9 getting 304:s form the server when requesting labels etc.
Make the primitive collections visitors generic over Exception types.
Log when recover index samples on startup
Log manual triggering of index sampling
Code cleanup
Log when evicting stale plans
Fix: unused imports
Fix for docs bug in import-tool manpage, and an additional example.
Remove the DependencyResolver dependency from the StoreMigrator.

Instead inject it in through the `migrateIfNeeded` method, because this happens at a time where the SchemaIndexProvider
has just been initialised anyway, so there's no need for any pseudo late-binding tricks.
Updates Browser changelogs for 2.2.0-M01

- Add recent merged featues.
Add bit of javadoc to primitive visitors

Also fix a bug where the offheap long long map would always produce a 0 value when visited.
Merge pull request #3418 from oskarhane/2.1-cache_buster

Make browsers fetch uncached files if updated.
Merge branch '2.1-maint'
Merge pull request #3483 from oskarhane/2.1-no-cache-ajax-get

Add no-cache headers on Ajax GET calls.
Merge remote-tracking branch 'origin/2.1-maint'
Merge pull request #3512 from oskarhane/2.2-append-browser-changelog

Updates Browser changelogs for 2.2.0-M01
Merge pull request #3503 from chrisvest/2.2-dep-free-migrator

Remove the DependencyResolver dependency from the StoreMigrator.
Merge pull request #3502 from chrisvest/2.2-prim-iter

Make the primitive collections visitors generic over Exception types.
Refactored test code