double-0 number tests

[tswaters]

Hey thanks for the great collection of JSON test specs!

I'm writing a parser for a personal project and loaded your json files into my fixtures directory. This resulted in a lot of missed failed parsing cases that I was able to resolve.

One thing I noticed is there are a few "leading zero" tests -

n_number_-01.json
n_number_neg_int_starting_with_zero.json
n_number_with_leading_zero.json

One case I see not tested here is multiple zeros followed by a frac / exp. These cases, should, I think, result in failed parsing:

00.0
-00.0
00e0
-00e0

My parser was accepting these before I added special cases for them - it may be good to add them to the test suite.