checkpoint fixing up App.v
checkpoint fixing up App.v

main stumbling block is that BYTEFILE never got fully integrated into
DIRTREE.  we need to know that every file (as opposed to directory)
in the tree has a [BYTEFILE.rep], but this fact is not in [DIRTREE.rep]..

perhaps BYTEFILE should export a type that captures a byte-level file
representation, [list byte], along with the inode attributes like
[INODE.IMTime], and [DIRTREE.TreeFile] should include that instead of
[BFILE.bfile].

mit-pdos/fscq-impl,mit-pdos/fscq-impl,mit-pdos/fscq-impl,mit-pdos/fscq-impl,mit-pdos/fscq-impl