Update iainb's pull request to merge cleanly + socket support + decode a buffer at a time + bugfixes

[otherwiseguy]

This pull request:

1. Updates iainb's pull request(Iterate over a stream of json objects + support new yajl version + bug fixes #33) which no longer applies cleanly
2. Adds the ability to use a socket as a stream by supporting recv() if read() is not available
3. Adds the ability to create a decoder and then decode strings iteratively. This could be useful if you are reading a buffer of characters at a time from a non-blocking socket. A contrived example:

import yajl

chars = list("""[1,2,3,{"key": "value"}]{"number": 1}[null]""")

d = yajl.Decoder(allow_multiple_values=True)

for c in chars:
    results = d.iterdecode(c)
    for r in results:
        print r
    else:
        print "Reading..."

4. In ianb's iterator patch, fixed the refcount on passing in bufsize which could cause a segfault.