Added a function to decode .tsx files

[chiguireitor]

Also fixed the Object struct to accept non-integer x, y, width and heights

[fardog]

this looks reasonable; thanks for the contribution! i'm unsure about the float change: i took the description from the docs:

The x coordinate of the object in pixels.

...to mean that it was an integer; do you have an example of a file generated from tiled that uses a float here? this will change the public API, but I've never considered it "locked" so that's cool if it generates tilesets this way.

[chiguireitor]

Yeah, latest Tiled exposes those "Objects" as floats... guess because they could be zoomed in etc.

[fardog]

sounds good to me. thanks again!