I deleted a large file but the disk space wasn't freed until I restarted
tachyon, apparently tachyon still had it open although I wasn't downloading it
at that time.

# TODO clean up random zombies

# TODO fuse filesystems may not be readable by root, so do setuid before stat

FIXME writer ? error: broken pipe -> tach dies:

	sched: fd 206 has an error: Connection timed out
	writev failed: Broken pipe
	sched: fd 133 has an error: Connection timed out
	sched: fd 134 has an error: Connection timed out
	writev failed: Broken pipe


TODO If-Modified-Since / 304 Not Modified, Accept-Encodings, Encoding (gzip).  cache gzip'd files?