Solicit data where non-BBR registrations outperform BBR

[rwblair]

There was a question asker today who showed interest in other methods than BBR for EPI registration. If we can find data where BBR fails or under performs we can better tune our registration or include offer other types.

[oesteban]

Definitely worth tracking this person and see where BBR fails. I'm under the impression that, once we finish with #101 (adding FreeSurfer to the stack), we'll quickly adopt bbregister which is basically BBR with some improvements.

[oesteban]

Done with #694