Re #7782. Use residentMem instead of availMem.

It *should* give about the same answer, but without the approximation
that nothing else on the system has changed.
Check for v2 Python API in systemtests setup.

Refs #7607
refs #7904 Enabled multi-threading in the test core
refs #7904 The test modified and should be it
Refs #7806 12 point change improved calibration
Re #7930 fix system test
Merge remote branch 'origin/feature/7930_fix_eqsans_norm_test'
refs #7228 Modified to reflect the changes to performance analysis
Merge remote-tracking branch 'origin/feature/7782_use_residentmem'
Merge remote-tracking branch 'origin/feature/7904_ConvToMDMultithreaded'
refs #7228 System tests: correct options in peak finding
Updated CNCS system test results.

Needed to account for subtracting TIB as events
refs #7952
Updated HYSPEC system test results.

Updated due to removing TIB as events now.
refs #7952
Correct typo in filename. refs #7952
Restoring data archive search option
Merge remote-tracking branch 'origin/feature/7952_systemtests_TIB_events'
Re #7975 modify system test for transmission fix
Re #7975 modify system test for transmission fix
Re #7975 add ref data for correct frame
CoverageTest for Loading ISIS Event data

There is not ISIS Event data in the Mantid repository. So, this SystemTest
was added to cover specific parts of the algorithm LoadEventNexus that
apply to ISIS data.

re #7985