Accessing .default in object crashes Slimit.

[Luke-SF]

Slimit crashes when trying to minify anything that tries to get a reference to .default. As a workaround, you can access it with object['default'].

>>> slimit.minify("var a={b:'b', c:'c', default:'def'}; console.log(a.default)")

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python27\lib\site-packages\slimit\minifier.py", line 38, in minify
    tree = parser.parse(text)
  File "C:\Python27\lib\site-packages\slimit\parser.py", line 93, in parse
    return self.parser.parse(text, lexer=self.lexer, debug=debug)
  File "C:\Python27\lib\site-packages\ply\yacc.py", line 265, in parse
    return self.parseopt_notrack(input,lexer,debug,tracking,tokenfunc)
  File "C:\Python27\lib\site-packages\ply\yacc.py", line 1047, in parseopt_notra
ck
    tok = self.errorfunc(errtoken)
  File "C:\Python27\lib\site-packages\slimit\parser.py", line 116, in p_error
    self._raise_syntax_error(token)
  File "C:\Python27\lib\site-packages\slimit\parser.py", line 89, in _raise_synt
ax_error
    self.lexer.prev_token, self.lexer.token())
SyntaxError: Unexpected token (DEFAULT, 'default') at 1:21 between LexToken(COMM
A,',',1,19) and LexToken(COLON,':',1,28)