support json type for mysql downstream (#2288)

* update go-mysql

* fix unit test

onlineddl: report an error when online ddl only matches only one regex (

#2182) (#2185)

cherrypick #1971 and #1990 to release-2.0.6 (#1991)

.*: update change-log for v2.0.5 (#1934) (#1936)

syncer: don't skip jobs from same event when comparing table checkpoi…

…nt (#1752) (#1783)

changelog: add change log for v2.0.4 (#1786) (#1787)

[hotfix] reduce safemode duration from 5 minutes to 1 minute

CHANGELOG: update release note for 2.0.3 (#1669) (#1675)

Hotfix again (#1641)

Update CHANGELOG.md (#1582)