Fixed small bug in drawing enemies (circles were slightly off center)
Added changes from Berlin
Rewrote Logger with C++ file IO
TODO: Implement timestamps for logger
TODO: Clear the file once it reaches 1MB (or something) in size
Added tile map class for drawing the level
Removed pointers where possible
Changed tile** to vector<tile> in level.cpp/hpp
removed constants from main.cpp
changed enemy position to a sf::Vector2i instead of two integers
Added some method stubs for loading a tile map into the level class
Working on drawing the level
fixed dumb bug (window.display was missing)
Drawing level is a little bit better but not really working yet
Fixed indices in tile_map.cpp (drawing works okay now)
Added test enemy  to main
Moving enemies now sort of works (TODO: Edge problem)
Moved some convenience methods to util.cpp
added some const modifiers
fixed util.hpp problem
Changed some stuff in move_enemy
Some more changes to move_enemy
adjusted Makefile
Small change in gamelogic.cpp for debugging.
gamelogic::move() works now
changed position values for enemy and tower classes to sf::Vector2i
added occupied field to the tile classes
Added missing methods to tile.cpp
gamelogic::move_enemy now marks the last tile the enemy visited as not occupied