Add news and a link to Lua Workshop 2014
remote:update's key can be scalar, closes #397
A fix and a test case for gh-421

"Granting a priivlege revokes an existing grant".

Fix a coding bug in grant/revoke Lua functions.

Update tests.

Fixes gh-421.
Merge branch 'master' of github.com:tarantool/tarantool
Update test result (changed a comment in a test).