make lines field public

[xyangst]

i want some lover-level control over the textarea, and currently there seems to no method to set or modify the text directly.

[sebszyller]

I'd like to bump this. This seems like a small change that enables different functionalities. E.g. currently, there isn't a an easy way to clear lines for no apparent reason. Deleting selection or recreating the text box is not ideal.