Made the Conf struct a Conf class.

Conf is now bound to a fixed config file that can be passed to the
constructor of Conf.
Added a function to change config parameters in the config file.

A keyword and a vector of parameters (strings) can be passed and then
the parameters of this keyword will be substituted in all the file.
Exchanged the random generator for RandomAIPlayer.
Merge branch 'dev' of github.com:chaot4/sea-crossing
Fixed useless endline outputs of SimpleGUIGame.
Moved the config to the right place.

There was a bug due to relative paths. Moving the config file to the
binary doesn't solve the whole problem of a relatively located
config file. We'll fix this later with an installation routine.
Tweaked camera and made some small bugfixes.
Fixed faulty default textures, added additional materials and placeholer textures.
Fixed a Segfault in the ResourceManager class.

The char array was one byte too short.
Fixed a bug in the board data.
Improved shading and extended materials. Added .gittributes.

Commiting should now be save for .ppm files.
Further improvements and fixes in surface shading.
Added temporary support for multiple lights, added another debug material.