LDAP queries need to be encoded as UTF-8

Bug: 1086505
Change-Id: I35ce938da135937d35f40df18ef0b05b6db1fd92
strip username, display name, and e-mail address fields

Now values consisting of only whitespace will not be accepted, since
they count as blank after stripping.

Bug: 997830
Change-Id: Id69e5fd2ec86e2a688631826c1bc9e66b32d6157