libedit changed its interface a while back. mariadb currently does not
recognize this interface and instead uses a static old readline version.
It does not link in the system readline due to licence incompatibility.
This commit adds a patch that enables mariadb to detect and use the
system libedit. The patch was sent upstream already ([1]).
[1] https://github.com/MariaDB/server/pull/1001
Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>
