No exit code.

[agirorn]

Should node-cpplint not exit with a exit code of something else than 0 when it encounters lint issues.
This would make it much more useful in build scripts.

$> node-cpplint src/**
✗ src/printer.cc
   25: Lines should be <= 80 characters long
$> echo $?
0

$> node-cpplint src/ok-file.cc
$> echo $?
0