Switch %r specifiers to '%s' in Public errors
This switch drops the preceding 'u' from strings within Public error messages.
This patch also addresses the related unfriendly 'u' from re-raising errors from netaddr.IPAddress by passing a bytestring through the function.
Also switched ValidationError to TypeError in validate_scalar per jcholast@redhat.com.
Ticket: https://fedorahosted.org/freeipa/ticket/3121
Ticket: https://fedorahosted.org/freeipa/ticket/2588