lrzip-next pre-production release

Major changes are:

• Inclusion of BZIP3 compression ( Kamila Szewczyk @kspalaiologos )
• Fixes for Mac memory computation
• Output formatting fixes
• Fix reading of archive comment from STDIN
• Revert to using #!/bin/sh for Mac systems
• Internal code fixes
• No changes to header format even with minor version bump. But BZIP3 mandated a bump.

Test and report. File issues as needed.