Move to centralised configuration file and enable debian packaging

This change enables the use of a single configuration
file to allow for configuration of database and
message queue at runtime, not compile.

This provides a base to enable configuration via
configuration management tools such as Chef and Puppet.

The configuration file is hard-coded to /etc/openrail/openrail.cfg
and is of a simple format:

db_name: database_name
db_user: database_user
db_pass: database_password
db_server: database_server
nr_user: network_rail_username
nr_pass: network_rail_password

This change set also provides the required code to create a debian package and install the relevant binaries to the correct location for the wiki documentation to work.