CHANGE COLUMN was blocked for TEXT and BLOB types. This fix applies to
things like TINYTEXT as well as the only difference internally is the
column width.
* TEXT and BLOB now have separate identifiers internally
* TEXT columns are identified as such in system catalog
* cpimport only requires hex input for BLOB, not TEXT
This patch allows the following syntax to change the current
autoincrement value for the table:
ALTER TABLE table_name COMMENT='autoincrement=value';
Where "value" is the new integer to be used.
