Add support for ignoring portions of code when formatting based on special region designator

[grochocki]

From @xlsupport in #9

I've had an issue with an ultra long Figures attribute in a PathGeometry, where I must keep the linebreaks. (it's a very long string qnd the highlighter goes bananas if it's flattened) I only want this block of lines ignored, but now I had to turn off the SaveOnExit which is a shame for all my other stuff.

It could be done using comment "blocks" similar to the "XAML Regions" extension.

[Spoelle]

My vote for this request ! I had problems with a fully styled combobox which was not showing text (selected item) anymore because of a fault reordening by this extension. Code.txt