Support logical arrays in blob columns without data type conversion

Based on the resolution of mym issue 3 and thus requires mym version 2.6.8+
fixed dj.GeneralRelvar/restrict that was broken in 3dbeca0. Also, removed one query to information schema with a regular query as part of fixing issue #22.
All restrictions now invoke dj.GeneralRelvar/restrict rather than append restrictions directly.
incremented version to 2.6.9
Merge branch 'future'