The game server will now look for the scripts in this order:
 - serverPath - config value
 - current working directory
 - the PKG_DATADIR #define

This replaces the rather hard to understand event dispatcher with a
probably even harder to understand templated library, but fortunately
we can rely on the available documentation.

Hopefully it will also help with the readability of our code and with
adding additional signals to other classes.

Added libsigc++ to README and Travis CI configuration.

Reviewed-by: Erik Schilling

It's easier to just talk about world data and to modify it as a whole.
If there is really a need to separate it, a project can still choose to do
that (and in whatever suitable way). There is no need to enforce this
separation or to do it in our example.

Reviewed-by: Erik Schilling

Reviewed-by: Ablu

Replaced by cmake.

Instead of searching for the configuration file in ~/.manaserv.xml, the
file is now expected to be in the working directory of the server. The
logs and statistics will also be written there.

This should make it easier to run differently configured servers on the
same machine, and should also be a bit more straight-forward to setup.

Reviewed-by: Yohann Ferreira

Reviewed-by: Jared Adams