ignore executables in bin/
ex4: added ex4 to master Makefile
ex5: added ex5 and Makefile entry
ex6: added ex6.c
ex6: break it!
ex6: fixed again
ex6: added precision to float formatting
ex6: added printf empty string
ex6: print distance as hexadecimal
ex6: fixed again
ex6: added ex6 to master Makefile