Update FlatSlider.xaml

User can define width of vertical slider / height of horizontal slider
Update Icons.xaml

Added the following icons:
appbar_bold
appbar_italic
appbar_underline
appbar_font
appbar_fontsize
appbar_fontsize_increase
appbar_fontsize_decrease
appbar_textcolor
appbar_marker
Update TransitioningContentControl.cs
Update MainWindow.xaml
Update MainWindow.xaml.cs
Update GlowWindow.xaml.cs

Fixes the cursor when owner.ResizeMode is ResizeMode.NoResize or ResizeMode.CanMinimize.
Fixes #952
Fix problem with to early SpeedUp
Create the base for our tests
Add the async targeting pack
Create a test application so we have all of our resources in place
Add some tests
´That shouldn't be there
Add some docs
Create some helpers
Add some more tests

Some of these are failing, we should fix that
Simplify the test helper
More tests
Use a default flyout
Now it is possible to use custom StringFormat ( "{}{0:N0} pcs." ) in XAML other than the standard ones (C,E,N,F,G)