Version 0.21 : Added array type
String.length() no more - now String.length
Added extra constructors to reduce confusion
Fixed checks against undefined
Added JSON.stringify and eval()
Nicer JSON indenting
Fixed function output in JSON
Added evaluateComplex
Fixed some reentrancy issues with evaluate/execute
symbol_base removed and replaced with 'scopes' stack
Added reference counting a proper tree structure
(Allowing pass by reference)
Allowed JSON output to output IDs, not strings
Added get/set for array indices
Changed Callbacks to include user data pointer
Added some support for objects
Added more Java-esque builtin functions
Added parsing of string defined with '
Changed nil to null as per spec, added 'undefined'
Now set variables with the correct scope, and treat unknown
as 'undefined' rather than failing
Added proper (I hope) handling of null and undefined
Added === check
Ability to define functions without names
Can now do "var mine = function(a,b) { ... };"
Slightly better 'trace' function
Added findChildOrCreateByPath function
Added simple test suite
Added skipping of blocks when not executing