Rename cmakelists.txt to CMakeLists.txt

CMakeLists.txt is the proper name, and the only one
that's accepted by CMake on case-sensitive filesystems.
src/GameFloor.h: Fix non-matching case in an include

This way, the compiler can find the file on case-sensitive filesystems.
Merge pull request #1 from crumblingstatue/case-sensitivity

Fix case-sensitivity issues
ADD New item: Blood Snake
FIX Mahogany staff not displayed on player
FIX Typo (MAHONAGY -> MAHOGANY)
FIX Merchant z-order bug
MOD Centrilazed data for items
MOD Centralized equip (with items)
FIX MAJOR game references missing
ADD More blood with blood snake
MOD Tilemaps optimisation (vertex array)
ADD Pause
ADD Mouse support (left click = fire)
Cleaning
FIX Minimap
ADD Save/Restore game
MOD Console ouput for releasing ressources
FIX Memory leaks / unreferenced... (Dr Memory)
FIX Loading a game generates always a fairy