Removed fg_pcap_cleanup() from public interface since it is only used internally
Added doxygen documentation for fg_pcap library
Don't ask for available congestion control algorithms on fg controller

Congestion control algorithms are set on daemon side. It doesn't make
any sense do take a look which congestion control algorithms the
controller can set. At a side effect: this commit fixes issue #61 as
well.
Merge pull request #163 from MarcelNehring/doxygen

Doxygen for fg_pcap
Merge pull request #165 from alexander-zimmermann/issue-61

Don't ask for available congestion control algorithms on fg controller