update dojo to point to dojo 1.8.3 in new repository

Point to new dojo github repository. Still points to dojo 1.8.3, i.e. the same version as before.

Note that something broke between dojo 1.8.3 and dojo 1.8.4 where parse.js gets a path error require()'ing marked.js, so this checkin just fixes the dojo submodule to point to the new repository w/out changing the version.   I'll investigate the dojo regression separately.