Gave up attempt to adapt line numbers
Made text editor to be auto resizable

Took the following steps:
1. Added the autogrow folder into Plugins
2. Added config.extraPlugins = 'autogrow'
3. See magic happen.
Adapted Share.js

This is experimental. It is just a shot in the dark because previously,
when I experimented with autosize.jquery.min.js, it did not affect the
textarea at all. This might not detect the text editor as a textarea.