Changed const to var to support node < 1.0
Changed const to var to support node < 1.0

manjeshpv/node-oauth2-server,mjsalinger/node-oauth2-server,oauthjs/node-oauth2-server,razvanz/node-oauth2-server,maxtruxa/node-oauth2-server,visvk/node-oauth2-server,thomseddon/node-oauth2-server