Histogram Improvements

Excluding reference samples from default plots

So far all samples matching a grouping code ("collation"; disease, publication etc.) have been included when generating the pre-computed CNV frequencies. However, the potential inclusion of normal/refernce samples sometimes lead to "dampened" CNV profiles. Now, samples labeled as "reference sample" (EFO:0009654) - a term we had introduced into the Experimental Factor Ontology - are excluded from pre-computed histograms. However, when e.g. calling up samples from publications using the search panel referencve samples will be included unless specifically excluded.

Pre-computed CNV Frequencies for PMID:22824167, now ommitting reference samples by default

All samples for PMID:22824167 were used when just retrieving by PMID