RFR 8059313: Enable keytool NSS test on Mac

[Wang Weijun]

Hi Vinnie

Can you review the fix at

  http://cr.openjdk.java.net/~weijun/8059313/webrev.00/

The test will try several places to look for NSS libs. If the machine has no Firefox or Thunderbird installed the NSS part won't run. At least this enables myself running NSS-related tests on my machine.

I tried to do the same for PKCS11Test.java but cannot find a way to set DYLD_LIBRARY_PATH (or equivalent settings in Java) inside the test. If you know how to do that, I'll be happy to include it as well. BTW, I added the environment variable on jtreg command line and among 62 pkcs11 tests, 54 pass and 8 fail. There seems to be some extra work.

Thanks
Max