(bunzip2_main): Read data from standard input if FILE argument is `-' or
omitted.
* include/usage.h (bunzip2_trivial_usage, bunzip2_full_usage): Rewrite.
* testsuite/bunzip2/bunzip2-reads-from-standard-input: New.
This code could be improvemed by
1) supporting more options,
2) Creating a shared crc table with gunzip, or perhaps generated on the fly.
3) Removing any remaining unneccessary code (e.g. if (noisy))