Merge pull request #22 from XForms/master

Merge with Main
Merge pull request #23 from XForms/master

Merge from main
Merge pull request #24 from XForms/master

Merge from main
Implementation changed (reworked) to function for iOS and Android as well (not only WP8), since the Appearing and Disappearing events where not received for the application's Main Page after OnPropertyChanging for CurrentPage property as with all other pages being navigated to/from.
Updated Windows Phone ExtendedScrollViewer
Added Android & iOS Screenshots
Merge pull request #242 from jguertl/master

Windows Phone ExtendedScrollViewer
Merge pull request #231 from WillooWisp/NavigationAware

Implementation changed (reworked) to function for iOS and Android as well
Charting Android fix
Merge pull request #248 from Snorvisable/master

Charting Android fix
updated autocomplete to reflect the code first pattern rather than xaml
cleaned up autocomplete files
Added PopupLayout view

PopupLayout added.
Android chart component fixed.
Merge branch 'master' of github.com:XForms/Xamarin-Forms-Labs

Conflicts:

src/Xamarin.Forms.Labs/Plugins/Charting/Xamarin.Forms.Labs.Charting.Droi
d/Controls/ChartSurface.cs
Android ExtendedScrollView
workaround selected item by @badstorm  close #236
Merge pull request #250 from dirric/master

autocomplete code cleanup
close ##249
update nuget spec beta4
Update Helper.