HandleRemover.c: style nits

Yes, I know I am annoying :^)
Merge pull request #1 from bassosimone/patch-1

HandleRemover.c: style nits
README.md: wrap long line
HandleRemover.c: add stdlib.h for system() prototype
HandleRemover.c: hint that strlen() is redundant
HandleRemover.c: indicate a place where the code may crash