Ensure that a loaded string starts with "{" or "["
Replaced literals with constant names
Better Strict checking of number values
Changed description of Basic JSONItem tests
Added unit test for loading badly formed JSON string
Updated README
Added CriticalSection property to prevent loading into the same object from two different threads
Added IsLoading method to test to see if an object is in the middle of a load
Loading to the same object in different threads will raise an exception
Merge branch 'feature/Two_double-quotes_should_be_rejected_on_load' into develop