Aggregate QC Stats Across Samples

[LeeBergstrand]

Add code to aggregate QC stats for the entire run.

• Parses the MultiQC file of each sample.
• Takes the FASTQC stats before and after QC.
• Calculates the percentage changed before and after QC for each sample.
• Writes all before QC stats, after QC stats, and percentage changes for all samples to a single file.

[LeeBergstrand]

@jmtsuji Fully tested and ready for your review.

The output looks like this:

Sample	Stage	Total Sequences	Total Bases (Mbp)	Sequence Length Min	Sequence Length Max	avg_sequence_length	median_sequence_length	%GC
blam	Before QC	24000.0	200.3	121.0	124032.0	8871.063208333330	2499.0	60.0
blam	After QC	827.0	7.7	754.0	96881.0	9365.918984280530	4999.0	59.0
blam	Change (%)	-96.55416666666670	-96.1557663504743	523.1404958677690	-21.89031862745100	5.578314169628950	100.04001600640300	-1.6666666666666700
cram	Before QC	24000.0	200.3	121.0	124032.0	8871.063208333330	2499.0	60.0
cram	After QC	827.0	7.7	754.0	96881.0	9365.918984280530	4999.0	59.0
cram	Change (%)	-96.55416666666670	-96.1557663504743	523.1404958677690	-21.89031862745100	5.578314169628950	100.04001600640300	-1.6666666666666700

[jmtsuji]

@LeeBergstrand Very nice addition to generate a tabular summary of QC changes for all samples. It will take me another couple days to review this new code, but I'll get back to you soon on this!