1.57 release

This is the typical follow-up bugfix release. Several things corrected and I even fooled around with some new things.

• In-game network chat is now enabled (press Enter to go in Chat mode)
• Keeping an IX active now provides a 5% bonus to all weapon damage, giving players an incentive to keep it around after upgrading
• Several AI tweaks, including Ornis not being so wastefully purchased, better base spread, and more defensive structures
• More info shown in the Host chatroom, including local IP
• AI MCV deploys now remove concrete underneath
• Fixed bug with Auto-repair costs
• Fixed bug with worms exploding out of the sand
• Fixed bug where flyers would drop units off into unexplored cells
• Fixed bug limiting human players to 6 Flying units or less
• Tweaked Ornis for tighter loops and better dogfights
• IX now has custom coloring (always hated that it was stuck at blue)
• Fixed bugs allowing units to react in some ways to allies as hostile units (including Ornis)
• AA Trikes are now very aggressive on Protect/Guard orders against Ornis
• Harkonnen now build more AA Trikes
• Fixed some draw problems with flyers
• Fixed inappropriate mission failure messages
• Non-music version now zips to fit on a 3.5" floppy (just thought I'd mention it for retro love)