Efficient Abstract Syntax Notation One (ASN.1) implementation.  This
 interface provides simple and efficient ASN.1 encoder and decoder.
 The encoder directly encodes BER encoded data blocks from variable
 argument list of ASN.1 types.  Multiple trees can be encoded at once
 and multiple nodes can be encoded into the tree at once.  By default
 encoder does not allocate any memory during encoding but a pre-allocated
 SilcStack is used as memory.

 The decoder directly decodes BER encoded data blocks into the correct
 types dictated by the variable argument list of ASN.1 types.  By
 default decoder does not allocate any memory during decoding but a
 pre-allocated SilcStack is used as memory.

 The encoding and decoding interface is simple.  silc_asn1_encode is used
 to encode and silc_asn1_decode to decode.  The actual ASN.1 is defined
 as variable argument list to the function.  Various macros can be used
 to encode and decode different ASN.1 types.  All types may also be used
 to encode and decode with various options (such as implicit and explicit
 tagging and defining specific class option).

 The implementation supports all the common ASN.1 types.  This
 implementation does not support advanced ASN.1 features like macros.

 References: ITU-T X.680 - X.693
 http://www.itu.int/ITU-T/studygroups/com17/languages/