setTranslationStart now calls setORF.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
mergeExons: call setORF

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
mergeExons: simplify

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
copyFeature: second arg was supposed to be optional

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
simplify setCDS

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
resizeExon: make more robust

* call setORF.
* If resizing causes siblings to overlap, they are merged.
* If resizing causes left edge become equal to right edge - delete exon.
* If resizing causes a change in translation start site - don't throw error.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>