Feature drawing panel

[ichan-mb]

A Panel that can be used to draw lines using your finger. As the DrawingPanel is native only, it must be contained in a NativeViewHost.

To use this control, You need to add a reference to Fuse.Controls.DrawingPanel and Fuse.ImageTools on your .unoproj file

Example

<App Background="White">
    <JavaScript>
        var drawing = DrawingPanel

        module.exports = {
            undoClicked: function(args) {
                drawing.undo();
            },
            redoClicked: function(args) {
                drawing.redo();
            },
            clearClicked: function(args) {
                drawing.clear();
            },
            clearHistoryClicked: function(args) {
                drawing.clearHistory();
            }
        }
    </JavaScript>
    <ClientPanel>
        <NativeViewHost>
            <DockPanel>
                <DrawingPanel ux:Name="DrawingPanel" />
                <StackPanel Height="70" ItemSpacing="10" Alignment="Center" Padding="10" Dock="Bottom" Orientation="Horizontal">
                    <Button Text="Undo" Clicked="{undoClicked}" />
                    <Button Text="Redo" Clicked="{redoClicked}"/>
                    <Button Text="Clear Canvas" Clicked="{clearClicked}"/>
                    <Button Text="Clear History" Clicked="{clearHistoryClicked}"/>
                </StackPanel>
            </DockPanel>
        </NativeViewHost>
    </ClientPanel>
</App>

This PR contains the following:

• Changelog
• Documentation
• Tests

[mortend]

This looks very good as usual and great effort :)