Support creation of a NobleSprite with an existing image or animation

[simjnd]

Solving #13

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In addition to creating a NobleSprite with a path to an image or spritesheet, this PR adds the possibility of creating a NobleSprite by giving supplying the function with:

• An image object (Graphics.image)
• An animation object (Noble.Animation)

This enables caching an image or spritesheet and then using it to instantiate several NobleSprite without loading it from disk everytime. You can now do:

-- Instantiate sprite with an image
local myImage = Graphics.image.new("path/to/image")
mySprite1 = NobleSprite(myImage)
mySprite2 = NobleSprite(myImage)

as well as

-- Instantiate sprite with an animation
local myAnimation = Noble.Animation.new("path/to/spritesheet")
myAnimation:addState("default", 1, animation.imageTable:getLength(), nil, true)
mySprite1 = NobleSprite(myAnimation)
mySprite2 = NobleSprite(myAnimation)

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I had to rename the __imageOrSpritesheet parameter to reflect these changes, and didn't think __imageOrSpritesheetOrAnimation was super catchy, so ended up opting for __view. The inline documentation has also been updated to detail these new usecases and show usage

[Mark-LaCroix]

"View" is a good term for this, and a familiar one from my days using Flash libraries, so I agree that's the right name for this variable/argument as it expands to become a somewhat more generic object.