[xmlsec] configure.in : NSS configuration

[Aleksey Sanin]

I got this directory structure from Red Hat 8 and 9 I am using :) Seems 
to work for me
and I can produce compatible RPMS. I would not mind if you'll make 
changes as
you want with one requirement: it should still work on my box after that :)

I am not sure I got your idea about the independency for NSS and NSPR.
You could not use NSS without NSPR. And you can use xmlsec w/o NSS.
The dependecy for LibXML2/XSLT is different (LibXML2 is *required* for 
xmlsec
and LibXSLT is always optional).

Anyway, I think the simplest way would be if you just prepare a diff and 
I'll take
a look at it. Configuration is always a nightmare and I would be glad to 
simplify
and standartize it. BTW, would it be possible to NSS to add something like
"nss-config" script? It would greatly simplify everything.

Aleksey