Dont call READCAPACITY from every single test.
Remove two arguments from the test signatures and turn them into globals.
remove the ret++ silliness. Tests return 0 : all ok, -2, skipped or -1 : test failed
Beyondeol tests: Add missing checks for optional opcodes
to SKIP tests where the target does not implement the opcode.
Improve the error reporting and make sure we always show the Sense we
received from the target when we get an unexpected error.
Check the size of the LUN and skip the test for luns that are too big.
For example skip testing READ10 on LUNs > 2^31 blocks etc.
