Bugfixes
- MySQL: Fix displaying empty text as a default value
- MySQL: Fix setting the default value of text and json fields
- MySQL: Display default values of binary columns (by @vrana)
- MySQL: Convert binary default value to hex when editing (by @vrana)
- MariaDB: Fix using "NULL" text as a default value of nullable column (issue #82)
- PostgreSQL PDO: Escape bytea values (by @vrana)