Uniqueness on insert is now determined by the hash of some columns stored in one new column with an unique index. This is more efficient than letting MySQL handle compund uniqueness of more columns
Fixed bugs in mysql migration command and added method for inserting to mysql using given connection
(cherry picked from commit 1b5a3b9)
Merge branch 'devel' into release-0.2.1
Merge branch 'master' into production_sensibledtu1k