Removing explicit --min-count and --max-count parameters to RunInstances.  Replacing them with a single --count parameter that defaults to 1 and allows a range specification as 1:10.  Fixed existing tests and added a few more.  Only known issue with this parameter ordering.  The --count parameter ends up at the end of the list.
Add error checking and meaningful error message if supplied value for --count is invalid.
Changing authored example for run-instances to use --count rather than --min-count and --max-count.
Unify paging params

* Remove built in paging params for paginated operations
* Add a ``--starting-token`` and a ``--max-items`` option
Add log message about modifying paging params