make use of the newer, better, remote helpers for prepare+activate OSD

Signed-off-by: Alfredo Deza <alfredo.deza@inktank.com>
create a helper to warn against incompatible hostnames

Signed-off-by: Alfredo Deza <alfredo.deza@inktank.com>
accept adjust_repos as an argument flag

Signed-off-by: Alfredo Deza <alfredo.deza@inktank.com>
add boolean flags for mangling repos

Signed-off-by: Alfredo Deza <alfredo.deza@inktank.com>