Logging should mention project name

[trac@…]

The log messages I get (in syslog) look like this:

Sep  1 17:52:13 sleepless Trac[main] WARNING: 500 Internal Error (Milestone milestone4 does not exist.)       
Sep  1 17:52:44 sleepless Trac[main] WARNING: 500 Internal Error (Milestone milestone3 does not exist.)       
Sep  1 17:53:15 sleepless Trac[main] WARNING: 500 Internal Error (Milestone milestone1 does not exist.)       
Sep  1 18:02:00 sleepless Trac[main] WARNING: 404 Not Found (No handler matched request to /foo)              

The problem is that we run about 10 Trac sites, with many more to come, so I have no idea which site in which to look for the error. We could redirect each site to its own logfile, but this just means more files to monitor. It'd be nice if the log message could be customized, or at least by default mention which site it's talking about.

[mgood]

Duplicate of #2844.