MFC r210794:

MFC r210794:
Allow file as a top source, it works with socket now.
This will allow top monitoring using socket/ssh tunnelling
of system without local symbols.

client:
pmcstat -R <ip>:<port> -T -r <symbolspath>
monitored device:
pmcstat -Sinstructions -O <ip>:<port>

- Move the file read in the event loop
- Initialize and clean log in all cases
- Preserve global stats value during top refresh
- Fix the rtld/line resolver that ignore '-r' prefix
- Support socket for '-R' (server mode)
- Display the statistics when exiting top mode

git-svn-id: svn://svn.freebsd.org/base/stable/8@211098 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f