Improved BrowserSettings

Added missing Browser Settings and replaced the Nullable<bool> with a
human readable BrowserSettingsState like in the CEF3
Removed unwanted changes from WebView and commited correct BrowserSettings.h
Reverted all changes from WebView.cs
Removed Browsersetting which are not supported in CEF3
Used Nullable<bool> again and changed names

The used boolean setting names now match the command-line options.
Removed trailing space and updated copyright year
Changed JavaScriptDisabled to JavascriptDisabled
Adding a name check to avoid unwanted exceptions.
WinForms - Add Reload, Print, Find, StopFinding, ViewSource methods to WebView
Remove find and stopfinding as they are not implemented in this branch yet
Load Url when Enter pressed or Go button clicked
Remove unused using statement
Update Url on LoadCompleted
Fix param names
Add NavStateChanged event handler for notification of CanGoBack, CanGoForward and CanReload
Add Stop, Back and Forward methods to WebView
Add Stop method to ManagedCefBrowserAdapter
Reference newly created Stop method in WebView
Set Form title on LoadComplete
Add LoadStartEventArgs for use with OnFrameLoadStart