memleak bugfix + cleanup + Makefile
- memleak bugfix as free() was missing
- dont call malloc() manually (the old way getline() always called realloc() anyway because of the way the malloc() was written [did not allocate enought memory for the string])
- small minor cleanup
- adding simple Makefile to build door challenge
- therefor if the program gets extended, its unlikly that
someone will forget to call free()
- also this gets rid of copy-paste free() calls (which look stupid)
- adding missing free() calls
- dont malloc ourselves as getline() also does a malloc
(and anyway called realloc before if the size_t was
smaller then the actual len(input-line) to behaviour
is the same!)
