Utilities/Sphinx: Make signatures linkable

Add signatures to the collection of observed objects (which can be
referenced elsewhere). Don't automatically strip parameters from a
:command: reference, as these may now link signatures. (Do, however,
munge them into 'text <ref>' form if they aren't already, as not doing
so adds an extra '()' for some reason.) Correspondingly, change xref
resolution to try to match 'command' when a ref like 'command(args)' is
not matched, so that existing links to commands that have not been
converted to use the new signature directive don't immediately break.
2 files changed