See also: https://github.com/vasi/pixz/issues

CLEANUP
	* massive cleanup
		* error handling
		* signal handling
		* globals
	* optimized settings
		* memory limit
		* cpu number
		* block size, for max threads on small files

BUGS
	* performance lags under IO?
	* slow input -> CPUs idle while waiting for input
	* safe extraction
	* sanity checks, from spec:
		- CRCs are already tested, i think?
		- backward size should match file
		- reserved flags must be zero
		- header vs footer flags
		- uncompressed size field vs actual uncompressed size
		- index vs actual blocks

EFFICIENCY
	* more efficient indexing: ranges? sorted? mtree?
	* circular buffer > linked list?

DOCUMENTATION
	* man pages
	* command help

FEATURES
	* support multiple streams
		* tarball append without decompression
	* other archive formats: cpio?
	* lzma-like API
	* recovery tool (already is, kinda)