some minor bugfixes, directory shuffling, added demo and utility disks
- added rudimentary error detection to some fileio routines - separated fileio lib into individual routine files - changed txtmode to amode - added automatic applesoft mode to binsave,binload - a couple minor bugfixes / tweaks
- added _RDUMP to required library - added MSWAP to common library - deleted full required library from each disk except #2, replaced with min versions (still need to update demos accordingly) - added beginnings of error handling in required library