Allow providing config to turn off parsing certain bigbed/bedtabix files as genes

[cmdcolin]

Sometimes very 'gene-like' bed12 represents a differnt data type

Example: Tandem duplications bed

We try to heuristically determine whether data is gene like, and if so, make it 'parse' as features with CDS subfeaturs, but we get trickd in this case

Could allow config to specifically force these as non-genes

part of effort to plot repeats