Finalized the Gesture Destign

I finalized the design for the gesture content view.

Based on some feedback I also implemented a CarouselView.  
The Carousel view is a display area on the page that acts as a carousel.  It supports swipe left and swipe right for navigation and has a simple (could be much improved on!) tickboard to show location.
The Carousel view also shows how our components can work together.  It uses a GestureContentView and a TemplateContentView and a TemplateSelector to achieve it's functionality.
Here is a sample of working Xaml for the GestureContentView:
```xml
 <labcontrols:GesturesContentView>
      <StackLayout>
        <Label Text="Gesture me NOW!">
          <lb:Gestures.Interests>
            <lb:GestureInterests>
              <lb:GestureInterest GestureType="SingleTap" GestureCommand="{Binding DumpParam}" GestureParameter="{Binding Ready}"/>
              <lb:GestureInterest GestureType="DoubleTap" GestureCommand="{Binding DumpParam}" GestureParameter="{Binding Ready}"/>
              <lb:GestureInterest GestureType="LongPress" GestureCommand="{Binding DumpParam}" GestureParameter="{Binding Ready}"/>
              <lb:GestureInterest GestureType="Swipe" Direction="Left,Up" GestureCommand="{Binding DumpParam}" GestureParameter="{Binding Ready}"/>
              <lb:GestureInterest GestureType="Swipe" Direction="Right" GestureCommand="{Binding DumpParam}" GestureParameter="{Binding Ready}"/>
              <lb:GestureInterest GestureType="Swipe" Direction="Up" GestureCommand="{Binding DumpParam}" GestureParameter="{Binding Ready}"/>
              <lb:GestureInterest GestureType="Swipe" Direction="Down" GestureCommand="{Binding DumpParam}" GestureParameter="{Binding Ready}"/>
            </lb:GestureInterests>
          </lb:Gestures.Interests>
        </Label>
        <Label Text="I do nothing"/>
      </StackLayout>
```
One thing to notice is the swipe gesture that only recognizes "Left,Up".  It will ignore left only or up only. 
Our full set of gestures are now:
SingleTap,DoubleTab,LongPress,SwipeUp,SwipeUpLeft,SwipeUpRight,SwipeDown,SwipeDownLeft,SwipeDownRight,SwipeLeft and SwipeRight.  Technically a swipe could be defined as SwipeUpDownRight, but that would never be selected.

The Carousel view is even simpler.
Here is working (if not exciting) xaml for it:
I put my templateselectors in the resources area, that isn't a requirement just a preference.
```xml
<ContentPage.Resources>
    <ResourceDictionary>
     <ext:BooleanNegationConverter x:Key="not"/>
      <ext:MessagePriorityToColor x:Key="alertcolor"/>
      <!--Top Bar Model template selector-->
      <labcontrols:TemplateSelector x:Key="summaryselector">
        <labcontrols:TemplateSelector.Templates>
          <labcontrols:DataTemplateWrapper x:TypeArguments="vm:MessagingSummary">
            <labcontrols:DataTemplateWrapper.WrappedTemplate>
              <DataTemplate>
                <ViewCell>
                  <Label Text="Oxy Plot"/>                
                </ViewCell>                
              </DataTemplate>
            </labcontrols:DataTemplateWrapper.WrappedTemplate>          
          </labcontrols:DataTemplateWrapper>
          <labcontrols:DataTemplateWrapper x:TypeArguments="vm:StudentGroups">
            <labcontrols:DataTemplateWrapper.WrappedTemplate>
              <DataTemplate>
                <ViewCell>
                  <Label Text="StudentGroups" />                 
                </ViewCell>
              </DataTemplate>
            </labcontrols:DataTemplateWrapper.WrappedTemplate>
          </labcontrols:DataTemplateWrapper>
          <labcontrols:DataTemplateWrapper x:TypeArguments="vm:StudentAttendance">
            <labcontrols:DataTemplateWrapper.WrappedTemplate>
              <DataTemplate>
                <ViewCell>
                  <StackLayout HorizontalOptions="FillAndExpand" Padding="10">
                    <controls:FancyLabel Text="{Binding ClassName}" HorizontalOptions="CenterAndExpand" BackgroundColor="Red"/>
                    <labcontrols:RepeaterView x:TypeArguments="vm:StudentGrouping" ItemsSource="{Binding Groups}" Spacing="5">
                      <labcontrols:RepeaterView.ItemTemplate>
                        <DataTemplate>
                          <StackLayout Orientation="Horizontal">
                            <Label HorizontalOptions="Start" Text="{Binding Name}"/>
                            <Label HorizontalOptions="End" Text="{Binding Count}"/>
                          </StackLayout>
                        </DataTemplate>
                      </labcontrols:RepeaterView.ItemTemplate>
                    </labcontrols:RepeaterView>
                  </StackLayout>
                </ViewCell>
              </DataTemplate>
            </labcontrols:DataTemplateWrapper.WrappedTemplate>
          </labcontrols:DataTemplateWrapper>

        </labcontrols:TemplateSelector.Templates>
      </labcontrols:TemplateSelector>
    </ResourceDictionary> 
  </ContentPage.Resources>
```
Later on in the page:
```xml
      <StackLayout Spacing="0" Orientation="Horizontal" HorizontalOptions="FillAndExpand" HeightRequest="200">
        <labcontrols:CarouselView x:TypeArguments="vm:IHomePageWidget" TemplateSelector="{StaticResource summaryselector}" ViewModels="{Binding Widgets}"/>        
      </StackLayout>

```