New expression functions

[mkaring]

I suggest a couple of new expression functions to control what protections are enabled where:

• [ ] Cyclomatic complexity - This allows to enable or disable protections for methods with a high or low cyclomatic complexity.
• [ ] Instruction count - This allows to enable or disable protections for very long or short methods.
• [ ] Reference count - The number of other methods that reference this type/member. This allows to enable or disable protections for methods that are rarely used.