"no_effect" INFO tag

[kpjonsson]

The "no_effect" label returned for example here:

svtk/svtk/annotation/classify_effect.py

Line 28 in eef0fc9

return 'no_effect'

...ought to be added to the VCF header:

svtk/svtk/annotation/annotate.py

Line 97 in eef0fc9

GENCODE_INFO = [

.