Release Candidate 4

This version introduces the SurfaceRenderer constructor and contains some final general fixes and additions for the current development cycle. Unless glaring issues will be found in this version, it should be the final one in the Release Candidate development cycle before the first stable release of Version Gold.

The SurfaceRenderer constructor has the same use as the SpriteRenderer constructor, adjusted for use with the Surface constructor, the functionalities of which are unchanged. Unlike Sprites, Surfaces are volatile and therefore require more setup, for which the event system can prove useful.

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Changes from Release Candidate 3:

Changes to existing content:
| Angle: Changed the construction of undefined as the first argument from constructing into the "Default value" construction type into the new "Empty" construction type.
| Scale.set(): Added Vector2 and Scale argument type support.
| Vector2/Vector4: Added Scale argument type support to the set(), setFloor(), setRound(), setCeil() methods.
| Vector4.getMiddle(): Changed the calculation method to a mean number.
| Vector4: Added functionality of returning separate value for each value pair to the getMinimum() and getMaximum() methods.
| Vector4: Merged getAngle1to2() and getAngle2to1() methods into a new getAngle() method and made it return the Angle constructor instead of a real number.

Additions:
+ SurfaceRenderer constructor.
+ Vector2: getAngle(), getDistance() methods.
+ Vector4: getClosest() method.
+ ArrayParser: getFirst(), getLast(), isEmpty() methods.

Fixes:
- SpriteRenderer: Fixed a Vector4 type location property not being duplicated on constructor copy.
- SpriteRenderer.isFunctional(): Added missing location and color property data types to the validation.
- SpriteRenderer.toString(): Added missing part, origin and target properties to the full output.

Instructions for conversion from the previous version:
• Angle: Adjust the code so that construction using undefined is replaced either by no argument, the default value of 0 or another real number.
• Vector4.getAngle1to2(): Change the used method to getAngle() and refer to the value property of the returned result instead.
• Vector4.getAngle2to1(): Change the used method to getAngle() with true as the first argument and refer to the value property of the returned result instead.