Add wait_until_fuse_mounted()

This was removed in a refactor in master, but it would take lots of work
to backport the entire refactor.

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Import teuthology tasks (firefly branch)

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Merge branch 'teuth_firefly' into tasks_firefly
Update module references

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Use newer orchestra API

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>
Use teuthology's DaemonGroup

It has timeout support.

Signed-off-by: Zack Cerza <zack.cerza@inktank.com>