LU-1526 tests: add version_code() and lustre_version_code()

LU-1526 tests: add version_code() and lustre_version_code()

This patch adds the version_code() and lustre_version_code()
functions into the test framework.

It also fixes the version number for the interoperability
of quota codes and reads the quota_type from MDS instead of
MGS.

Test-Parameters: envdefinitions=SLOW=yes,ENABLE_QUOTA=yes testlist=conf-sanity,ost-pools,sanity-quota
Signed-off-by: Yu Jian <yujian@whamcloud.com>
Change-Id: I5a4d26fb71a7e56fa8497688ee2492ec90c446f8
Reviewed-on: http://review.whamcloud.com/4754
Tested-by: Hudson
Reviewed-by: Yang Sheng <yang.sheng@intel.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Niu Yawei <niu@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>