First version of tcplim.

After fixing integer overflows in quota processing and addping protection against corrpution, it should be stable enough.
Current features:
1. iptables redirection
2. total and per-stream limiting
3. enumarating connections
4. changing limits on the fly (both total and individual)
5. counting rate of connections
6. manually closing connections
7. showing total uploaded and downloaded for connections
8. trivial prioritisation for connections

Planned features:
1. netstat integration to show program names
2. better configuration and console interface
3. more advanced and useful prioritisation of connections; auto-detecting of total bandwidth
4. multiple workers to handle more connnections (current limit is around 500)
5. "polycing script" to flexibly choose indidual connection parameters
6. total uploaded/downloaded, total bandwith display
7. connection groups, "fair" distribution by considering source IPs
8. qtcplim - GUI for tcplim to allow automatic configuration, plotting speed and setting limits with GUI.