Ds 2045

Added item stats endpoints to REST API 

rest/items/[handle]/stats?[start=2014-01-01]&[end=2014-06-30]&[interval={day|month|year}]
rest/items/[handle]/stats/{download/view}?[start=2014-01-01]&[end=2014-06-30]&[interval={day|month|year}]
rest/items/search/stats?[search parameter]&[start=2014-01-01]&[end=2014-06-30]&[interval={day|month|year}]
rest/items/search/stats/{download/view}?[search parameter]&[start=2014-01-01]&[end=2014-06-30]&[interval={day|month|year}]