Use XML output and remove HTML scraping functions

- Used xml output in simpleSearch (sXML=1) and parsed response
- Removed obsolete functions
Extract PodnapisiClient to own class using XML-RPC

First implementation of Podnapisi XML RPC client.
Use XML-RPC with optional Preferences to get DownoadURL's. Fallback to web scraping if authentication unsuccesful.
Merge branch 'master' of https://github.com/bramwalet/PodnapisiSubtitles.bundle