Added a JSON reader and file reading, follow instructions in the description to know how to make it work.

First, we're using "Tiled" as our map editor now. Get it here:
http://www.mapeditor.org/

Second, Go through "File -> Build Settings... -> Player Settings...".
Clicking Player Settings will open something up in the inspector. Click
on "Other Settings", then set "Api Compatibility Level" to ".Net 2.0"
instead of ".Net 2.0 Subset". This will get rid of the Reflection
errors.