Implement diagnostic and code fix for SA1101 PrefixLocalCallsWithThis

[sharwell]

Fixes #35

The number of test cases is large to say the least. Basically I need to choose one item from each of the categories below and build a test for that set of conditions.

• Element type
  • Type
  • Method
  • Property
  • Field
  • Event
  • Parameter
  • Local
• Inheritance
  • New element
  • Override
  • Interface implementation
  • Explicit interface implementation
  • Hides static base element
  • Hides instance base element
• Is Static
  • True
  • False
• Expression type
  • Assignment to element
  • Read from (simple, e.g. var x = this.Property;)
    • For methods this is a reference to the method group
  • Read from (qualified, e.g. var x = this.Property.GetHashCode();)
  • nameof expression
• Expression location
  • Attribute value
  • In static member
  • In instance member
  • Field initializer for static field
  • Field initializer for instance field
  • String interpolation
  • Documentation comment
• Receiver
  • Current instance (or the containing type if Is Static is true)
  • Another instance

This gives a maximum of 4704 tests for complete coverage, although some combinations do not make since (e.g. you cannot assign to an element within a documentation comment or nameof expression).

[sharwell]

I think the only reasonable way to do the testing for this is create a helper method that takes an enum value representing each of the above category and builds a test for that case.

[sharwell]

nameof poses a remarkably bizarre set of challenges for this feature.

• Instance members of a type can be referenced without an instance of the type available.
• The nameof expression can be qualified with this when the target of the expression is an instance member, as long as you are in a context where this is available.
• If the target of the expression is a method group, you can use this even if none of the methods in the group are instance methods.
• The expression can always be qualified with the name of the containing class, regardless of whether or not the target is an instance member.

[sharwell]

Since I really want to get this feature in a release, I'm implemented initial testing on a variety of edge cases in the above list.

[sharwell]

I'm merging this one now that tests are in place so it gets included in the Alpha 2 release.