lines longer than 100 will simply warn (no error)

Generic.Files.LineLength sniff will now warn whenever a line is longer
than 100 characters and error out on line longer than 9999 which would
never be reached hopefully.

The idea is to be able to ignore the line lenght in 'strict' Jenkins jobs.

Change-Id: I19475a97beda04e4d27d7ce3ee33f4770be26bb4