add upnp mediarenderer backend

set useUPnP true in config.json to use.

Jira-issue: WP-1229
Merge pull request #15 from aldafu/WP-1229-add-service-for-UPnP-MediaRenderer

add upnp mediarenderer backend
test3
test N+1
XBMC json2rpc implementation using upnp discovery
Jira: WP-1226
Fixing minor bug
Jira: WP-1226
refinement for xbmc implementation. Minor fixes.
Jira-issue: WP-1226
fixing timers and unregister method
Jira-issue: WP-1226
fixing unregister and minor bugs
Jira-issue: WP-1226
fixed bug on undeleted connection object
Jira-issue: WP-1226
cleaning up rebase mess
Jira: WP-1226
Merge pull request #16 from michelemorello/WP-1226

Wp 1226