Make non-public API methods static where applicable

[lahma]

Some empty methods were removed as they were not used and not part of public API.

[tonyqus]

What's the advantage of converting non-static methods to static? faster?

[lahma]

The CA1822 rule description has pretty good explanation:

Members that do not access instance data or call instance methods can be marked as static (Shared in Visual Basic). After you mark the methods as static, the compiler will emit nonvirtual call sites to these members. Emitting nonvirtual call sites will prevent a check at run time for each call that makes sure that the current object pointer is non-null. This can achieve a measurable performance gain for performance-sensitive code. In some cases, the failure to access the current object instance represents a correctness issue.

[tonyqus]

LGTM