Alterações na distribuição 3.20.10

New insert type: INSERT INTO ... SELECT ...

MEDIUMBLOB fixed.
Fixed bug in ALTER TABLE and BLOB values.
SELECT ... INTO OUTFILE now creates the file in the current database directory.
DROP TABLE now can take a list of tables.
Oracle synonym DESCRIBE (DESC).
Changes to make_binary_distribution.
Added some comments to installation instructions about configure's C++ link test.
Added --without-perl option to configure.
Lots of small portability changes.