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).