XD-2351 fix pom generation
 added explicit exclusions required for pom generation
XD-2408 Fix tap re-deploy issue

   - When a tap is undeployed, the associated tappable module output channel entry was
removed from plugin. We should remove the entry only if the main stream is
undeployed.
      - This way when a tap is re-deployed, the corresponding tap channel
is bound to the module output channel.
XD-2397: Fix CNFE in tcp-client module
Update `grunt-contrib-imagemin` to `0.9.2`
XD-2107/1048 SpEL for metric name and counter value in aggregate counters
* XD-2107 - Aggregate counter can increment by SpEL over message
* XD-1048 - Dynamically select metric name using SpEL
* Fix metric name option
* Fix typo and rich-gauge phantom creation
XD-2332 Provide Server-Side Cron Expression Validation

* Add validation REST endpoint
* Add AngularJS directive to perform async validation
XD-2332 Code Review Changes

* Add integration tests for ValidationController
* Rename `CronValidationDto` to `CronValidation`
* Move `CronValidation` to REST domain module