WinForms - Dispose of BrowserSettings after browser created
WinForms - Dispose of BrowserSettings after browser created

BrowserSettings must be set before the call to CefBrowserHost::CreateBrowser for this reason we enforce these checks.
Throw exception if attempt to set BrowserSettings after browser has been created

Initially I was going to make BrowserSettings a private set, unfortunately that probably won't work if you are using the designer
as there would be no way to instantiate a new instance. It was possible to lazy initialize in the get method, that doesn't really provide
a descriptive error message, I could have updated the documentation to describe the behaviour, unfortunately people just don't really the docs.

Livit/CefSharp,Livit/CefSharp,Livit/CefSharp,Livit/CefSharp