XD-547 Add AggregateCounter display
- Added AggregateCounter display command with from, to, (XD-665)lastHours, lastDays, resolution and pattern options
- Fixed missing aggregatecounter value into counts array for the given interval
 - the end time interval 'value' was not added into the counts array as the size
   calculated was missing the end time interval.
  - Fixed DeepAggregateCountResourceAssembler, RedisAggregateCounterRepository & InMemoryAggregateCounter
- Added joda-time dependency to spring-xd-rest-client project
 - Handle from/to joda time query-params in AggregateCounterTemplate

XD-547 Fix AggregateCounterTests to include the end time's metric
Remove unwanted throws clause from AggregateCounterOperation's retrieve method.
Fix doc generation now that we have mutually exclusive options