Update MahApps.Metro/Styles/Controls.ContextMenu.xaml

When a sub menu is popped-up, it's foreground colour would follow the parent. Since the parent's foreground is white, its foreground is also white. The update force the foreground colour the dirty way.
updated ignore file to mute NCrunch-generated files
Allow user-specified EllipseDiameter
included a sample project which tests the change
Added a demo project for illustrating the AccentColorBrush issue.
grouping demo projects under solution dir
Fixed the AccentColorBrush color issue.
Merge remote-tracking branch 'remotes/mahapps_head/master'
CustomVisualStates for TransitioningContentControl
tweaking the demo layouts
Change the foreground colour of the MenuItem when disabled.

Added Input Gesture into MenuItem.

Added brush resource for disabled MenuItem and associated it.
updated demo to include a disabled form item
updated readme
added repro for issue #318
bugfix for #269 - set the RenderTransformOrigin value
#253 - providing IsCheckedChanged hook for ToggleSwitch consumers
updated sample to use event handler
Support toolbar
Add appropriate icons
Update MahApps.Metro/Styles/Controls.ContextMenu.xaml

Added the resource brush used in the version which has been pulled into the main branch.