Remove XML namespaces ("{....}") from json hash keys

Currently the json output from xml2json looks like this:

    $ ./xml2json.py -t xml2json test.xml | head -n 1 | python -c 'import sys; import json; print json.dumps(json.loads(sys.stdin.read()), indent=4, sort_keys=True)' | head -n 10
    {
        "{https://route53.amazonaws.com/doc/2012-12-12/}ListHostedZonesResponse": {
            "{https://route53.amazonaws.com/doc/2012-12-12/}HostedZones": {
                "{https://route53.amazonaws.com/doc/2012-12-12/}HostedZone": [
                    {

... That's really difficult for humans to grok, and doesn't really help when expecting to use the results as a dictionary in some other python code. This patch fixes the output to be a little more human friendly:

    $ ./xml2json.py -t xml2json test.xml | head -n 1 | python -c 'import sys; import json; print json.dumps(json.loads(sys.stdin.read()), indent=4, sort_keys=True)' | head -n 10
    {
        "ListHostedZonesResponse": {
            "HostedZones": {
                "HostedZone": [
                    {