Bugfixes and Equality Unification

[Chris3606]

• Added full serialization system support to PolarCoordinate
• Added tuple compatibility functions to PolarCoordinate
• Created and utilized new IMatchable<T> interface for defining mutable type equality comparisons (fixes #44)
  • Removed IEquatable<T> implementations from all mutable types
  • Removed Equals, operator==, operator!=, and GetHashCode implementations from all mutable types
  • Replaced all above function with IMatchable<T> implementation
  • Implemented IMatchable<T> on immutable types (mirroring Equals) to provide parity
• Renamed Equals extension methods to Matches, and added extension methods for built in types (fixes #50)
• Refactored unit tests to deal with IMatchable<T> and correctly test all serialization aspects
• Bumped version number and changelog to prepare for release