I was wondering whether you'd accept a pull request to modify how bam-indexes are found by csam.
Currently, for a given "xxx.bam", the csaw functions die if xxx.bam.bai can't be found.
As a suggestion, I think csaw should allow either "xxx.bam.bai" (samtools default) or "xxx.bai" (picard default) names for indexes (and die if neither are present; choose the newer of the two if both are present).