v0.4.12

*) Filter settings fixed for data sets with reads that don't have the
same length
*) BAM support improved
*) Better paired end support for BAM/SAM
*) Added parameters for read groups
*) Commandline output is now written to stderr
*) SAM/BAM output is written to stdou if -o/--output is omitted
*) Better handling of empty reads in FASTA/Q files
*) Change NAME filed to PN in SAM/BAM header
*) Fixed a bug that prevented NextGenMap from terminating when executed
in python scripts