I have to jump through a few hoops now with the NSS library
initialization since another part of an application may have already
initialized NSS by the time Curl gets invoked. This patch is more
careful to only shutdown the NSS library if Curl did the initialization.

It also adds in a bit of code to set the default ciphers if the app that
call NSS_Init* did not call NSS_SetDomesticPolicy() or set specific
ciphers. One might argue that this lets other application developers get
lazy and/or they aren't using the NSS API correctly, and you'd be right.
  But still, this will avoid terribly difficult-to-trace crashes and is
generally helpful.

rob