Because OStringList is an optarg, we must specify "a!" to
zend_parse_parameters.
However zend_parse_parameters still returns this as a *long* rather
than a NULL (or empty array) so positively check that it has returned
an array.
The visibility field in action replaces in_fish, in_docs and internal.
The defined types are:
VPublic:
A public API. This is exported and documented in all language
bindings, and in guestfish.
VStateTest:
A public API which queries the library state machine. It is exported
and documented in all language bindings, but not guestfish.
VBindTest:
An internal API used only for testing language bindings. It is
guarded by GUESTFS_PRIVATE in the C api, but exported by all other
language bindings as it is required for testing. If language
bindings offer any way to guard use of these apis, that mechanism
should be used. It is not documented anywhere.
VDebug:
A debugging API. It is exported by all language bindings, and in
guestfish, but is not documented anywhere.
VInternal:
An internal-only API. It is guarded by GUESTFS_PRIVATE in the C api,
and not exported at all in any other language binding. It is not
documented anywhere.
This is a simple renaming of the files/modules.
Note that in OCaml, module names are derived from filenames by
capitalizing the first letter. Thus the old module names had the form
"Generator_api_versions". The new modules names have the form
"Api_versions".
