added support for caching the nnindex
added support for caching the nnindex

aws623/ocropy,catethos/ocropy,zuphilip/ocropy,lunactic/ocropy,catethos/ocropy,zuphilip/ocropy,olivernina/ocropy,lunactic/ocropy,catethos/ocropy,dnacreative/ocropy,loveheaven/ocropy,loveheaven/ocropy,lunactic/ocropy,braddockcg/ocropy,kba/ocropy,dnacreative/ocropy,amitdo/ocropy,liuqingjie/Ocropy,olivernina/ocropy,mapbased/ocropy,dnacreative/ocropy,stweil/ocropy,amitdo/ocropy,aws623/ocropy,tmbdev/ocropy,kba/ocropy,liuqingjie/Ocropy,aws623/ocropy,liuqingjie/Ocropy,tmbdev/ocropy,zuphilip/ocropy,danvk/ocropy,stweil/ocropy,amitdo/ocropy,danvk/ocropy,braddockcg/ocropy,kba/ocropy,loveheaven/ocropy,danvk/ocropy,braddockcg/ocropy,olivernina/ocropy,tmbdev/ocropy,mapbased/ocropy,stweil/ocropy,mapbased/ocropy