1. update vendor
  2. `use db` can't be explain, it will print err log at explain.go

* fix #176

  JSON datatype only support utf8mb4 now

* splitstatement support optimizer hint

  https://dev.mysql.com/doc/refman/8.0/en/optimizer-hints.html
  https://dev.mysql.com/doc/refman/8.0/en/comments.html

* vendor daily update

  single table select * don't auto-complete table name
  multi table select tb1.*, tb2.* auto-complete table name

  compatibly with old version(<0.10.0)

  support FULLTEXT INDEX syntax

  we change mymysql to go-sql-driver and use insert unhex()
  for any dangerous data type.

	修改：     doc/example/main_test.sh

merge by xiaomi

  1. remove Index_Comment in ShowIndex function
  2. remove mysql client deps in Makefile

  1. update vendor pingcap/parser
  2. Makefile add docker contain stop wait
  3. -report-type=rewrite when syntax error, print error info not empty