check null pointer in tscSql.c.

add test

Feature/vpeer

fix print typo in general/db/basic5.sim.

turn on the arbitrator code

refCount may be negative if vnodeRelease is called appropriately

make output clear and add general/db testcases.

add assert there in case it happens

Feature/sync

Feature/balance

fix stop_dnodes.sh with postpone socket cleanup and same timestamp is…

add query in shared library to support python test script execution.

fix stop_dnodes.sh with postpone socket cleanup and same timestamp issue in general/table/basic2.sim.

[TD-96]

# Conflicts:
#	src/vnode/main/src/vnodeMain.c