Update the front page (release date).
Fix erroneous commit for box-net branch
fix erroneous box.digest test
sophia: closes gh-629: support for multi-space transactions
Fixes for OPENTAR-90
Merge branch 'stable'

Conflicts:
	extra/rpm/tarantool.rpm.spec.in
Update tests after sophia push.
Add more tests for roles.

Test the session cache of global access.
Test lack of grant option.
Implement error checks in grant/revoke.
Add a few more tests for roles.

Check ER_GRANT error.

Check distinct sources of privileges.
Implement role 'replication'. Fixes gh-660.

Update tests to use this role.
Fix erroneous KEY constants
Fix a few spelling errors in box-protocol.rst.
Merge branch 'master' of https://github.com/tarantool/tarantool