added option for key/values in select fields
added option for key/values in select fields

tagyangyang/jsonform,imkevinyang/jsonform,suricactus/jsonform,capriza/jsonform,mrthan/jsonform-rails,yklykl530/jsonform,iainbeeston/jsonform,ulion/jsonform,capriza/jsonform,widgetworks/jsonform,ulion/jsonform,globocom/jsonform,jsonform/jsonform,imkevinyang/jsonform,joshfire/jsonform,tagyangyang/jsonform,nishant8BITS/jsonform,jsonform/jsonform,widgetworks/jsonform,nishant8BITS/jsonform,globocom/jsonform,suricactus/jsonform,joshfire/jsonform