Improve output from (primarily) security commands:
* Fix a few missing EOLs on output, some in security, some in other commands
* Fix check_grant_blockers to discard the 'error' tuple label from verify_permissions before adding the message to the collected errors
* Stop swallowing errors in riak_core_console
* Translate errors in riak_core_console
* Drop problematic single-role clause for add_grant/add_revoke, was only used for unit tests, could result in an infinite loop if invoked incorrectly from shell