Issue #12 - Fixing wrong offset with newlines

[joshuafeldman]

Fixing wrong offset with newlines and ensuring the content offset doesn't intentionally get set to a negative value which is causing the text to jump in a perfectly sized text view with a single line.

Not taking any credit for these fixes since they come from other people's suggestions. But there hasn't been any pull requests to update the main repository with these changes. So figured I would do one 👍