Second public pre-release

This second pre-release of bamrescue is able to rescue non-corrupted bgzf block from corrupted bam files and write them to new, non-corrupted bam files that are ready for use.

It also features a progress bar showing the number of corrupted bgzf blocks as they are found while checking.

While not production ready yet, it is already usable if you need to work with corrupted bam files.