Make WPF DropDownButton's Popup stuck to button.
ColorBoard ellipse positioning improved

ColorBoard mouse handle bug fixed
ColorPicker popup fixed to stick to button
Cancel button for ColorPicker
inital commit introducing new ExtendedColorLegend control so far

1) workable on WPF
2) Compilable on Silverlight
Merge remote-tracking branch 'bbnova/master'

Conflicts:
	Controls/Orc.Toolkit.SL/DropDownButton/DropDownButton.cs
Extended color legend with color selection on double click now
Merge remote-tracking branch 'auz34/master'
stylecop