Mplayer fixes

[togfoxy]

Changes proposed in this pull request.

• routines to trigger and manage host disconnection (via exiting game)
• routines to trigger and manage client disconnection (via exiting game)
• removed fixed IP address so outside connections should now work
• quitGame can now be safely invoked from multiple places
• added 3 blank lines between functions as per style guide
• stops client/host being a client/host if already connected

Fixes #248 Fixes #246 Fixes #125

[togfoxy]

So this PR provides some nice robustness when hosts/clients do odd things. I'm sure there are some edge cases but this addresses three issues.

[togfoxy]

Good points. 247 is documented. I'll document the rest. Thanks!