Pkcs12 modifications

Beware: as written in 720349f49f7b82a5e0fffa3cfe763a020e267000 this breaks older calls in order to ensure no broken pkcs12 is generated.

This is needed in order to get more relevant  argument names, especially the misleading "$pkey_pass".

As said in #33, unit-tests aren't present at all for pkcs12 stuff, might be a bit more complicated as it needs a correct key/crt pair. With a chain cert if possible, in order to test acf5226e0094450b73461aebf679a23adfedc282 (I'm using it, working fine, but unit-tests will ensure it does work with next modifications ;) ).