Songs aegis behavior updated. Bonus correction

- Fixed bug 8412 http://hercules.ws/board/tracker/issue-8412-songs/ Now songs auto-refreshes every 3 seconds.
- Musical Lesson bonus rounded down for BA_ASSASSINCROSS.
Fixes song affecting caster without link
In linux enable thin-stream mode.

It should reduce latency in some cases.

See more info here: https://www.kernel.org/doc/Documentation/networking/tcp-thin.txt
Merge pull request #421 from csnv/songredo

Songs aegis behavior updated. Bonus correction
Merge pull request #422 from 4144/thinsock

In linux enable thin-stream mode.

Note: If anyone has a reason to disable this, please tell us, and we'll turn it into a compile-time option.