HPM Update

- Custom Packet Support
- Custom Data Struct Support (currently append-able to map_session_data and socket_data)
- Char Server Support
- Login Server Support
http://hercules.ws/board/topic/1934-hercules-plugin-manager-update/
Documentation will soon be updated in http://hercules.ws/wiki/HPM

Signed-off-by: shennetsind <ind@henn.et>