See below what mongodump looks like when run with --version as opposed to what mongod looks like:

$~/Downloads/mongodump --version
mongodump version: 2.8.0-rc0
$ mongod --version
db version v2.8.0-rc1-pre-
git version: e6ff142766cf8cbfa04a9c6acc5cb8ced3ea9fb3

Need to bring --version for all tools into line with what mongod does, as well as updating our release process to append -pre- for all non-BUMP commits.