yajl-ruby

just an FYI, not important

Noticed the problem because rest-graph requires 'yajl/json_gem'.

yajl-ruby is a new JSON coder and decoder library,
rest-graph is picking it if available. the order is:

1. yajl/json_gem (fastest)
2. json (most seen)
3. json_pure (pure ruby version! most compatibility, slowest)

we are not using it by the way... only used on my computer.
and i notice that there's one incompatibility:

json and json_pure won't parse this:
"a string"
but yajl/json_gem do, and parses it as a string.
actually, if i remember correctly, this is not a json too.
json is either wrapped with {} or []
"a string" is a string, this is true, but can't be top level.

anyway, we didn't suffer this i think,
i just notice this because of running rest-graph test with rubinius,
which didn't install yajl on my computer.

btw, rubinius is still very slow, but it works.