Light edit to protover warnings.

   * If you need to remove a version from this list, you need to make sure that

   * it is not listed in the _current consensuses_: just removing it from the

   * required list below is NOT ENOUGH.  You need to remove it from the

   * required list, and THEN let the authorities update and vote on new

   * required list, and THEN let the authorities upgrade and vote on new

   * consensuses without it. Only once those consensuses are out is it safe to

   * remove from this list.

   *

   * One concrete example of a very dangerous race that could occur:

   *

   * If the client required protocol "HSDir=1-2" is then changed in the code

   * and released to "HSDir=2" while the consensus stills lists "HSDir=1-2",

   * Suppose that the client supports protocols "HsDir=1-2" and the consensus

   * requires protocols "HsDir=1-2.  If the client supported protocol list is

   * then changed to "HSDir=2", while the consensus stills lists "HSDir=1-2",

   * then these clients, even very recent ones, will shut down because they

   * don't support "HSDir=1".

   *

   * And so, changes need to be done in lockstep as described above.

   * And so, changes need to be done in strict sequence as described above.

   *

   * XXX: WARNING!

   */

 * network unless their presence is causing serious active harm.

 *

 * The following required and recommended lists MUST be changed BEFORE the

 * supported list above is changed in order for those lists to appear in the

 * consensus BEFORE.

 * supported list above is changed, so that these lists appear in the

 * consensus BEFORE clients need them.

 *

 * Please, see the warning in protocol_get_supported_versions().

 *