regression: change option '-m' to '-t'

Option '-m' is used to chose a set of tables to test, so directly
change it to '-t' to keep consistency with other subsystems.

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>
db:mysqldb: add ifRecordExist() method

Add ifRecordExist() method to return if a record already exists
in a data table.

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>
regression: update strategy assistant

Update strategy assistant function to contain more informations
required to do assistance or simulation.

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>