API for managing NSS modules

[edewata]

JSS should provide a platform-independent mechanism to manage modules in an NSS database (e.g. adding a module, checking module status). This is needed to add p11-kit-trust module in PKI (see dogtagpki/pki#265)

Per discussion with @rjrelyea, there might be several options:

• find the full path of libnss3.so first, then find pkcs11/p11-kit-trust.so relative to that path
• use RPM macro to find the full path of pkcs11/p11-kit-trust.so

See also https://github.com/nss-dev/nss/blob/master/lib/freebl/genload.c.