[TD-888] change timer init sequence

replace read/write with tread/twrite in wal.

Build taosd before jdbc tests

Hotfix/to regression

fix td-789: memory leak

[TD-815] crash while drop vgroup

Added -x --continue-on-exception option to the crash_gen tool

Feature/crash gen, now running well again.

Removed crash_gen dependency on other test code, now it only depends on official Python Taos library

change log

Hotfix/crash

add csv test

add test case for compressMsgSize

WAL version set error

[modify sim cases]

[TD-764]

re-raise exception in sql.py instead of exit.

fix td-885

Hotfix/test