Valgrind friendly openssl, if getenv("CFENGINE_TEST_PURIFY_OPENSSL")

Even if you compile your openssl with -DPURIFY and no-asm, valgrind
still outputs a very long list of uninitialised variable warnings. It
turns out that the "blinding" feature of openssl is the culprit.
Merge pull request #1648 from jimis/minor

Valgrind friendly openssl, if getenv("CFENGINE_TEST_PURIFY_OPENSSL")