Minor refactoring in config package.
Release mutex before changing working directory.

Signed-off-by: Jim Teeuwen <jimteeuwen@gmail.com>
Adds error handling to config.SetRoot call in program
setup. The chdir call in there might fail and we want to
know about it.

Additionally, write the current pid to a file on startup.
This file may be needed by supervisors like systemd in order
to deal with monitoring of a process which can keep forking
itself. Rhis file is saved in `$PROFILE/ircb.pid` and is
updated every time the bot forks itself.

Signed-off-by: Jim Teeuwen <jimteeuwen@gmail.com>
Fixes configuration file path code in module package.
The returned file path should be relative to the profile
root, since the bot chdirs into this directory on startup.

Signed-off-by: Jim Teeuwen <jimteeuwen@gmail.com>
Bumps minor version number.

Signed-off-by: Jim Teeuwen <jimteeuwen@gmail.com>