ensure compatibility with 6.2u5 to pass "standards" test

[admin]

To be able to use the name "Grid Engine", we have to pass the "standards"
test in EXHIBIT B of the SISSL by running the testsuite using a (non-existent)
"reference" version (see sge/LICENCES/SISSL,
sge/LICENCES/standards, and sge/doc/compatibility_test.html​).
Although the current version should be compatible with the last of the
Sun code, it may not be compatible on the wire with any released version, e.g.
because of [3532] and other possible GDI changes in 6.2u6.
It would be difficult to argue against compatibility with 6.2u5, as counting,
so we need to get the tests running and, if necessary, introduce a compatibility
mode that hides changes like [3532] and allows us to pass the test, probably
dependent on an environment variable. I don't know how sustainable that will
be long-term.

[dlove]

Seems not to be necessary with Univa's legal opinion on the licence.
We're compatible with Univa v8 now.