Enable y-scroll on textarea resize

[share-with-me]

The originalText textarea populates itself with text input by user and dynamically resizes to the height of the content. However, if we resize the originalText textarea (vertically) by manually dragging the bottom corner, and decrease its height as compared to the text content height, it does not give a y-scroll. Thus, a user would not be able to view the entire contents of the textarea. I would like to add a y-scroll to the originalText in the above scenario. The following link has the demo of the issue: Link

Please note that the destinationText textarea does enable y-scroll in case its height decreases as compared to its contents height and I aim to have a similar functionality for originalText too!
I am using Firefox. I am unable to test this on Chrome and Safari as both of them are not giving me an option to resize the textarea in the first place.

[share-with-me]

Here is an attempt to achieve above functionality. Please note the y-scroll on originalText when its height changes with respect to its contents.
Demo
Would refactor to create a patch soon.

[sushain97]

Assigning to myself since #152 is blocked by me figuring out sane requirements.