Prior to this commit only those C structs for SET and SEQUENCE types
could be decorated. Now those for CHOICE types also can be decorated.
We could further extend this to SET OF and SEQUENCE OF types if it
proves useful.
This commits allows `heim_object_t` as a type and causes the generated
code to use the `heim_retain()` and `heim_release()` functions for
copying and releasing values of such types.
Also, now one can have more than one decoration per-type.
This adds support for asn1_compile --decorate=... variation that causes
decoration of an ASN.1 SET/SEQUENCE type with a field of a non-ASN.1
type.
This means we can now have an ASN.1 type to represent a request that can
then have a "hidden" field -- hidden in that it is neither encoded nor
decoded. This field will be copied and freed when the decoration is of
an ASN.1 type or of a external, C type that comes with copy constructor
and destructor functions. Decoration with a `void *` field which is
neither copied nor freed is also supported.
We may end up using this to, for example, replace the `hdb_entry_ex`
type by decorating `HDB_entry` with a C type that points to the `HDB` in
which the entry was found or to which it should be written.
