a new config arg 'min-cardinality' for index column selection

  syntax check now only use tidb parser, no vEnv dependency.

  bit type not config as int, when two columns compare will
  give ARG.003 suggestion.

  fix #154, #157 by the way

  不建议使用连续判断
  SELECT * FROM tbl WHERE col = col = 'abc'

add COL.007 RuleMaxTextColsCount & update ARG.003 rule content

fix SetLooger && update filepath

add new heuristic rule RuleColumnNotAllowType COL.018

  compatible with windows file path, regression filepath.Join

  support allow-collates checks

  go test ./... -update

  ref: https://github.com/XiaoMi/soar/pull/147

  Thanks @xiyangxixian

  COL.015 text/blob default value only tobe `NULL`;
  COL.012 text/blob `NOT NULL` CONSTRAINT may be danagerous;

fix #141

fix #89 

fix index advisor give wrong database name, `optimizer_xx` is tempora…