laco.c: factor out useless variables
laco.h: remove useless comments

All of these are obvious.
Convert laco_destroyLacoState to return a bool
CMakeLists: Add more CFLAGS
main.c: remove useless 'return 0'

We're not using c89.
src/*.c: Reorder headers + add space before keywords.
src/*.{c,h}: More comment cleanup