Merge branch 'cef/2171' of https://github.com/cefsharp/CefSharp into cef/2171
Merge branch 'cef/2171' of https://github.com/cefsharp/CefSharp into cef/2171
Implementing invalidate
Implementing invalidate
Merge branch 'cef/2171' of https://github.com/Bodekaer/CefSharp into cef/2171

Conflicts:
	CefSharp.Core/CefSharp.Core.vcxproj
Removing test line, was committed by mistake
Adjusting formatting to use space instead of tab
Reverting changes to build.ps1 file
Removing unnecessary whiteline changes
Changing copyright symbol to avoid encoding issue
Removing Invalidate call from inside OnIsVisibleChanged, instead making it a method so it can be called from other place if necessary
Re-add copyright symbol
Improve Xml comment and add `Invalidate` method to IWpfWebBrowser interface