Update esprima, and function and spread transpilers

function.js:
- remove support of 'function expression'. This will fixed #21
* Update 'arrow function' support (for example: right behave for 'let a
= a=>a;')

spread.js:
* refactoring of spread-as-function-call

Update local esprima (These changes are not included in official
'harmony' branch):
+ add workaround for this issue
http://code.google.com/p/esprima/issues/detail?id=483
(VariableDeclarator + ArrowFunctionExpression with named parameter throw
'Unexpected token =>')
+ wrapTracking(parseArguments) - similar issue as
http://code.google.com/p/esprima/issues/detail?id=484 (range for
parseParams)
* Merge latest changes from 'harmony' branch into my local esprima this
will fixed #20

Update tests