Add textbox option to disable character wrapping.

Squashed commit of the following:

commit e20617dab50efe9b672e50629af5057f02740c15
Author: Gregory Brown <gregory.t.brown@gmail.com>
Date:   Mon Jul 21 09:18:10 2014 -0400

    Add API doc

commit a8dad73bb2bec75a2c66cb40ea3304965eff9d32
Merge: b14344e dd92069
Author: Gregory Brown <gregory.t.brown@gmail.com>
Date:   Mon Jul 21 09:08:56 2014 -0400

    Resolve merge conflicts

commit b14344edfee7a20638a7169f8ff7ebaea2432ffe
Author: James Coleman <jtc331@gmail.com>
Date:   Tue Jun 5 13:38:58 2012 -0400

    Add textbox option to disable character wrapping.

    This is particularly helpful in combination with :overflow => :shrink_to_fit. With :disable_wrap_by_char => true you can ensure that the shrinking maintains whole words.