Party EXP Fix and cave fix

Multiplayer EXP gains have been fixed (host was previously receiving twice as much EXP as clients)

EXP from summon-kills have also been fixed across multiplayer.

There was an inaccessible cave South-East of ryen-sek that has now been fixed. Previously you could not move after entering the cave and all you could do was go back out.

I am currently away for little while as I am moving business premises for my main job, please understand I will be working on the game when I can and I will be back in full force once this has stabilised. Thank you so much for your patience, help and bug reporting!