Issue #1338 - Part 4: Initialize NSS with desired run-time values.
    
    This NSS version (and onward) has variables to enable PKDBF rounds for
    master password hardening (combating brute-force guessing).
    Since we use DBM, we need to explicitly enable iteration counts in DBM
    mode, and adjust the rounds used with a lower maximum because the PKDBF
    routine for DBM is considerably slower for which the NSS default of
    10,000 is debilitatingly high.
    The method for this is run-time configuration through environment
    variables. We set these prior to NSS initialization from nsAppRunner.cpp
    so the NSS lib picks them up and allows us to continue using the DBM
    cert/key stores with stored rounds per record.