[obexd] Packaging fixes. Contributes to JB#17036

- Fixed obexd --nodaemon argument to --nodetach
- Added daemon start/stop commands to obexd-server preun/postun
- Fixed obex.service to call obexd-wrapper
Merge pull request #3 from hmallat/obexd-packaging-fixes

[obexd] Packaging fixes. Contributes to JB#17036