add criteria generator; translate in selections ids and groups
add racksh gem
translate date range
extract selection translators
sort option translator
add timestamps to all sortable models
use criteria translator for GET /events
use criteria translator for GET /franchises
doc optional params to GET /events and /franchises
fix starts/ends at param parsing
update sortBy and sortDirection docs
set GET /franchises note
use criteria translator for GET /groups
doc ids param for GET /events, /franchises, /groups
parse multiple values in selection args

Updated the in selection translator so that it accepts a comma-separated
list of args.
added fields option translator

Now you can scope query results by specifying comma-separated list of
fields.
Merge pull request #78 from yobennett/query-for-mongoid-3.1.2

Updated library code for Mongoid 3.1.2