snap to nucleotide boundaries when resizing exon
snap to nucleotide boundaries when resizing exon

fixes #44

Signed-off-by: Harsh Gupta <c4bd8559369e527b4bb1785ff84e8ff50fde87c0@gmail.com>

wurmlab/afra,kimrutherford/afra,wurmlab/afra,kimrutherford/afra,kimrutherford/afra,wurmlab/afra,kimrutherford/afra,kimrutherford/afra,wurmlab/afra