Added PKCS#10 support to ASN1js

Tonight I added PKCS#10 support to #ASN1js.

…by parsing RFC 2986 and, unfortunately, by applying a minimal set of patches to simplify its ASN.1 dialect as my parser doesn't yet support it all… interesting how older RFCs used a much more complicated #ASN1 than more recent ones.

Just a point pro the hypothesis "recent RFCs use simpler ASN.1 syntax", today I added parsing of RFC 4210 & 4211 and it was quite straightforward.