Fix config file

This patch improves the way that we load the config files.

Now, configuration files will be looked for and used in the following order:

[1] /etc/deuce/config.ini
[2] $(HOME)/.deuce/config.ini
[3] [sys.prefix]/config/deuce.ini
[4] /ini/config.ini

Location 1 is for system installed deuce
Location 2 is for home dir configuration
Location 3 is for virtual-env and/or system wide configuration
Location 4 is for development purposes

With this patch, one can simply pip install deuce from git and run deuce-server. Deuce will load and use the default config file (assuming that no other config files exist on the system, of course). 


Not a hold-up, but...

All the paths except /etc/deuce are system-independent. I know we're only planning on using Linux ourselves, but might it be good to add a couple lines prior to L49 to detect Non-Windows or Windows and add either L50 or an os.path.join(os.environ['PROGRAMDATA'], "deuce", CONFIG_FILENAME) respectively instead based on the result?

Just a thought, and as I said - not a hold-up.