Fix PTR header top margin on Gingerbread and lower

Turns out you have to set gravity to Top for the negative margin to work properly
on <= Gingerbread.
Changed ViewWrapper's readonly "State" property to a getter that returns the current refresh state
Merge pull request #2 from ansuria/master

Expose the ViewWrapper class's current refresh state

The State property already existed but hadn't been hooked up to return the refresh_state value.
Update README.md

Correct an example usage error.
Show alternative method of retrieving reference to the IPullToRefresharpView.
More README updates

Correct method for retrieving a wrapped view (don't use IPullToRefresharpView as the type).
Add some mention of how to use a custom header and that you can use your own strings.
Update sample with test for ListView with fast scroll enabled
Add handling for fast scroll

This solution is a bit naive, but it accomplishes the goal of not interfering with fast scroll, when enabled.
The downside is that if a list view has fast scroll enabled, the left portion of the screen defined by
fastscroll_thumb_width will never trigger pull to refresh.
Add custom attribute for manually setting fastscroll thumb width
Added ExpandableListView support and Dutch locale
Updated sample to include ExpandableListView
Merge pull request #7 from Gameleon12/master

Added ExpandableListView support and Dutch locale

Thanks for the contribution!
fix conflicts, upstream merge