Enable Travis Continuous Integration in legacy

This patch fixes autotools build and adds build configuration for otserv 0.6.x
Example link to the build result under travis [![Build Status](https://secure.travis-ci.org/adakraz/server.png?branch=legacy-dev)](http://travis-ci.org/adakraz/server)

I assumed that autotools are the primary method of building the project. Notify me if this is not the case.

Apart from merging the branch, a repository administrator needs to enable builds in Travis (will also complete #12 ). You may want to keep this issue open until this is resolved.