Clean and fix definitions of options.

- Provide new helper functions in `Goptions` on the model of
  `declare_bool_option_and_ref`;

- Use these helper functions in many parts of the code base
  (encapsulates the corresponding references);

- Move almost all options from `declare_string_option` to
  `declare_stringopt_option` (only "Warnings" continue to use the
  former).  This means that these options now support `Unset` to get
  back to the default setting.  Note that there is a naming
  misalignment since `declare_int_option` is similar to
  `declare_stringopt_option` and supports `Unset`.  When "Warning" is
  eventually migrated to support `Unset` as well, we can remove
  `declare_string_option` and rename `declare_stringopt_option` to
  `declare_string_option`.

- For some vernac options and flags that have an equivalent
  command-line option or flag, implement it like the standard `-set`
  and `-unset`.

1 files changed, 0 insertions, 2 deletions

diff --git a/engine/uState.mli b/engine/uState.mli
index 3959373ead..cd1c9a174e 100644
--- a/engine/uState.mli
+++ b/engine/uState.mli
@@ -69,8 +69,6 @@ val univ_entry : poly:bool -> t -> Entries.universes_entry
 
 (** {5 Constraints handling} *)
 
-val drop_weak_constraints : bool ref
-
 val add_constraints : t -> Univ.Constraint.t -> t
 (**
   @raise UniversesDiffer when universes differ