There are currently two hard limits for the number of BBCodes
allowed. One is enforced by the type of the `bbcode_id` column,
the other by an hard limit in `acp/acp_bbcode.php`. However this
limit can never be reached due to the size of the database column.
Suggested fix involves adding a new constant to define the max.
number of BBCodes (as with smilies) and chaning the database
column from a tinyint to a smallint to actually allow 1511 BBCodes
PHPBB3-7778