BUG FIX Frequency Maps

Fix "only direct code matches" frequencies

Pre-computed Progenetix CNV frequency histograms (e.g. for NCIT codes) are based samples from all child terms; e.g. NCIT:C3262 will display an overview of all neoplasias, although no single case has this specific code.

However, there had been a bug when under specific circumstances (code has some mapped samples and code has more samples in child terms) only the direct matches were used to compute the frequencies although the full number of samples was indicated in the plot legend. FIXED.