New Development Version
Throw Exception if we're not passed an Activity. Closes #170.
Revert removeViewImmediate() change. Closes #179
Ensure the Header View is displayed at the correct location

Mainly for system ui visibility changes. Closes #169 and #174.
Remove unnecessary Handler instance
Small code formatting fixes
Allow setting refreshable views via the object rather than ID.

Will close #162.
Use SmoothProgressBar
Update build.gradle to set minSdkVersion
Fix compiler warning
New CenterProgressDrawable. Not working yet.
Add Bitdeli badge to README
SmoothProgressBar is now fully integrated. Closes #171.

Still need to expose the library options.
Merge branch 'SmoothProgressBar' into development
Merge branch 'development' of github.com:chrisbanes/ActionBar-PullToRefresh into development
Fix ProgressBar parent style
Workaround for #182
Fix ABC sample name
Revert header layout change.

Make sure progress bar is initially invisible for layout pass.
Fix ProgressBar drawable on Gingerbread