LP #1595912: pt-table-sync and pt-table-checksum do not allow to specify user to check slave if --recursion-method processlist or host is used

**Reported in Launchpad by Sveta Smirnova last update 16-08-2016 09:15:21

There is no way to specify custom user for pt-ts and pt-tc to check slave if recursion-method processlist or host is used.

This is feature request.

Suggested fix: add option --slave-user or similar

Fix together with bug #1595678