Fix a crash on single end data, where getProperPairFlag throws an
Exception if called on a read which isn't paired end.
Rename the fastqc_icon.png to bamqc_icon.png so we don't get an error in
the report from a missing file.  We probably need to design a new logo
rather than re-using the FastQC one.
Added the reporting data for ChromosomeReadDensity