Add JSON support in communication with zencoder.com

[aleksey-korolev]

zencoder.com supports communication in both json (by default) and xml.
ZencoderClient.createJob(ZencoderJob job) returns Document and there's no way to instruct ZencoderClient to use JSON.
JSON support has to be added.
There are 2 options:

1. ZencoderClient uses json format for communication and returns json response from server as a String which is later processed by developer's code upon developer's discretion.
2. ZencoderClient parses json string from server and constructs JSON object using one of JSON libraries, e.g. jackson or json-simple.

[drallgood]

hmmm...

Is there a reason why someone would need JSON and can't work with XML?

I didn't want to complicate the code by supporting two different output formats. That's why I never included JSON support.

[aleksey-korolev]

Well, I think JSON would be less expensive in parsing, but this is just my speculation, I didn't do any tests yet.

[drallgood]

Hmm.. Don't think so. Might depend on the parser, though.