In updateDate added updateBAT2 which use seek(offset, 1) i.e. relative location in searching

 performance testing using 1M file took 100mins and the relative overhead is still not stable.

 Also the original files are not updated correctly.

 Will change to Java for further investigation
Merge remote-tracking branch 'origin/master'

Conflicts:
	exp_update/config.py
	exp_update/exp_updateData.py