Retry failed reads
Disable EXT2 writes; add experimental tmpfs

This is still a work in progress. ext2 writes are quite broken, so they
have been completely disabled, but there's a new tmpfs mounted to /tmp
that you can try to poke at. I'm still fixing up quirks in the VFS that
make it incompatible with a bunch of stuff, but I did manage to write
some files with vim, and swap files appear to be working at least
somewhat. It's all still broken as fuck.