* Add quotes to `$` in shell scripts
This is necessary for correct processing of quotes in the
user command.
* Minor improvements to AclCommand messages
* Use a principal with a space in `SslEndToEndAuthorizationTest`
This passed without any other changes, but good avoid regressions.
* Clean-up `TestSslUtils`:
Remove unused methods, fix unnecessary verbosity and don't set security.protocol (it should be done at a higher-level).
Author: Ismael Juma <ismael@juma.me.uk>
Reviewers: Grant Henke <granthenke@gmail.com>, Jun Rao <junrao@gmail.com
Closes#818 from ijuma/kafka-3152-kafka-acl-space-in-principal
Ismael Juma
Jay Kreps
Neha Narkhede