ImageData:setPixel accepting a table

Issue #582 resolved
created an issue

If ImageData:setPixel could accept a table, it would be consistent with everything else which sets colors (,, ParticleSystem:setColors and SpriteBatch:setColor).

While Lua's unpack function could be used on a table argument to ImageData:setPixel, it could also be used on a table argument to every other function which sets colors except for ParticleSystem:setColors.