Use contentType from request headers if available
Use contentType from request headers if available

Fixes issue #96

oberhamsi/ringojs,ringo/ringojs,oberhamsi/ringojs,ashwinrayaprolu1984/ringojs,ashwinrayaprolu1984/ringojs,ringo/ringojs,ringo/ringojs,Transcordia/ringojs,ashwinrayaprolu1984/ringojs,Transcordia/ringojs,Transcordia/ringojs,ashwinrayaprolu1984/ringojs,ringo/ringojs,oberhamsi/ringojs,Transcordia/ringojs