Add logging module

Route all logging functions through this module. Support both logging to
a file and syslog.
Error log configuration
Merge pull request #45 from dlundquist/logging

Add logging module
Updating Debian package to use pidfile

Fixes #42
Updating travis.yml to use same pidfile location as Debian package
Update .travis.yml

Use new pidfile location. Include user in test configuration, test stopping and uninstalling package
Merge branch 'master' into nonblocking-connect

Conflicts:
	.travis.yml
	src/connection.c