Google Summer of Code Update - Bridging UPnP networks

Developments since the last update -

* Added support to maintain the state of local UPnP networks through the concept of proxy devices and services at a single point. It eliminates the need to query the local network each time a request comes from the foreign host.

* Completed the HTTP proxy to route the data between internal and external networks. Since UPnP uses UDP multicast packets to discover services, which is not possible in our case, that will also be done through a dedicated HTTP proxy.

* For each local device we need to run a proxy, automated this feature with the concept of maintaining state of local UPnP devices, and proxies are started/stopped as devices or services come and go.

Next tasks -

* Zeeshan has provided a great feedback on the work so far, there are a couple of changes to be made in the design and class hierarchies.

* Once the present features have been implemented and finalized, the next task would be to support UPnP events across different hosts.