hub 1.12.2

• Explicitly paginate just help text instead of all output

  Doing so enables us to clear the screen reliably upon exiting the pager
  without risking single-page output being swallowed.

• Don't allow man page width to exceed 120 characters

• Show hub <command> -h short usage help on stdout

• Fix hub browse on detached HEAD

• Fix hub compare for branch names with slashes in them

• Fix hub am for Enterprise URLs