fs: reclaim blocks when deleting files
cons: refactor fs dumping
cache: work towards deletion
fs: require 9p version message before we talk to the world
snap: keep root in snapshot tree.
cons: add 'show free' to show free ranges
tree: apply messages to the right files
pack: clean up junky dprints.
dump: fix printing Odelete messages
lookup: collect all the way up the tree.
splitleaf: switch blocks in the same loop
blk: don't double-free blocks, split pivot splits
check: better dump formatting, misc fixes.
newblk: don't clobber refs on cached blocks
cons: extract into its own file
cache: extract into its own file
console: add 'show cache' for debugging
blk: possibly fix entry reuse
all: replace error returns with constants.
tree: refcount blocks correctly
cons: improve output
bptr: move to 24 byte block pointers with generations
refactor: move to Bptr struct
scan: fix tree boundary condition
fscons: tweak 'show' to take args
fs: handle truncation a bit better, accumulate messages correctly
scan: don't drop files in directory listing
tree: refactor to allow multiple parallel trees
blk: fix freelist implementaton
fs: allocate blocks correctly, group insertions, snapshot
tree: shrink buffer when flushing deletions.