fix for listview dividers not being displayed for rows disabled with isEnabled() adapter method

fixes the bug by wrapping pull to refresh header and footer into FixedViewInfo objects as described in this blog post:
http://blog.uncommons.org/2013/01/24/android-listview-fixing-missingblank-dividers/

This fix resolves the issue for me. All examples in the sample project work fine with this fix applied.