Regularly dump TCP_INFO statistics of outgoing connections

Backport from PR #401 to 1.7.

(cherry picked from commit b88bd91447cb143ae5a6a08ca54a9d5166314d6e)

Conflicts:
	src/libcutil.clib

Closes #401
Merge pull request #456 from Incubaid/tcpinfo-for-1.7

Regularly dump TCP_INFO statistics of outgoing connections