Fix logging facility setup in headerparserhandler.py.
Fix logging facility setup in headerparserhandler.py.

server parameter must be passed to apache.log_error method. Additionally,
we need to set log level of the logger for passing logs to Apache to DEBUG to
pass all logs to Apache. I also leave some comment about LogLevel directive.
Review URL: http://codereview.appspot.com/4550061
googlearchive/pywebsocket,googlearchive/pywebsocket,GoogleChromeLabs/pywebsocket3,GoogleChromeLabs/pywebsocket3,google/pywebsocket,google/pywebsocket,googlearchive/pywebsocket,GoogleChromeLabs/pywebsocket3,google/pywebsocket