Remove/replace feed proxies

[turicas]

Currently we are indexing results from sites like feedproxy.google.com, but they aren't really the original source of the information.

We may find an way to avoid indexing it or replace it by the original source of information.

[fccoelho]

I agree, but we need some tests to figure out how to find this out on the the information returned by the Universal feedparser (originally by Mark Pilgim).
I was talking to @flavioamieiro, that we should put some effort to do a major overhaul of the feedparser code, or develop one of our own, that does not have these problems.