Add --verbosity=N option. N is 1-5 and defaults to 3. For now, level 1 will
mute printing of cracked passwords to screen. Level 4 will add some extra
output from OpenCL and level 2 will mute some other. More to come.
Merge branch 'bleeding-jumbo' into memdbg

* bleeding-jumbo:
  Add --verbosity=N option. N is 1-5 and defaults to 3. For now, level 1 will mute printing of cracked passwords to screen. Level 4 will add some extra output from OpenCL and level 2 will mute some other. More to come.