New MLDonkey release 2.7.5

- Support for compressed ipfilter.dat files
- giFT GUI: Authentication support
- HDD space check
- Block/allow IPs by country codes
- Allow compile with Ocaml 3.09.2 CVS code
- EDK: New default URL for server list download
- BT: New command "startbt" to force the start of a torrent download
- BT: Automatically start new torrents stored in $MLDONKEY_DIR/torrents/incoming