This library has two purposes:

1. primary: to allow the easy preparation of bootable disk images
   containing Mirage kernels

2. secondary: to provide a simple key=value store for Mirage
   applications

Note that "filesystems" are inherently legacy systems which modern
Mirage applications will not use directly. The most likely use for this
library is in booting a Mirage application via some kind of disk image.

Known limitations

• can only make FAT16 filesystems

• no VFAT support

• no exFAT support (see #78)

• corrupts under concurrent writes

PRs welcome to address any of these limitations!