Add map_free

map_free should be able to quickly free the map created by map_create
Change stricmp to strcasecmp

My system doesn't have stricmp, using posix standard strcasecmp instead
Add check for running map_get on empty map

Prevents an error when you use map_get on a map which is empty
Add CMakeLists.txt for use in my build
Remove trailing spaces
Add basic checks to see if memory was allocated

Make sure the memory was able to be allocated before using it
Merge pull request #2 from knivey/master

fixed stuff, added map_free to free map's memory