Make `process_item_attrs` look the same while keeping logic intact.

Additionaly added explicit handling (or ignoring if you will)
`<<"ask">>` attribute.

Now you can easily see differance in JID usage.
IMPORTANT Merge branch 'master' into feature/mod_roster_backend_rewrite

Conflicts:
	apps/ejabberd/src/mod_roster_odbc.erl

Conlict due to commit f856d0d , in which only changes to
`mod_roster_odbc` consist replacing strings with birany strings.  In my
branch, all of those where moved to `mod_roster_odbc_back` module, so in
this merege I took my version `mod_roster_odbc` and implement all
necessary changes into `mod_roster_odbc_back` by hand.