MB-12709: Replace argparse with optparse

Since argparse module doesn't exists before python 2.7, we have
to replace it with optparse which exists since python 2.4.

Change-Id: I23a76ae0e127a90b95fc10db5131701ff15b5ff7
Reviewed-on: http://review.couchbase.org/43413
Reviewed-by: Bin Cui <bin.cui@gmail.com>
Tested-by: Bin Cui <bin.cui@gmail.com>