draft PR for supporting ircut get/set and genericizing service call

[jeyrb]

This is working on my hik camera now.

Rather than clone all the existing code for get and put, I've refactored a new method that will make any http call. It can also make a PUT request using XML from a previous GET request and overriding based on keyword args, so very easy to create new PUT calls ( so long as still able to find an ISAPI doc pdf!)

If you like this, don't merge but let me know. I'll add tests, and refactor the existing get/put to use the new call_service

[mezz64]

I'm opening to making a change like this. My main concern is covering the edge cases though. There have been quite a few tweaks included here and there to work with different camera behavior and I would want to make sure those are retained.