TODO.

TODO

 * Document the recent additions (CHANGES + doc).
+  - API documentation:
+      present functions in a sensible order
+      organize them into groups?
+      use internal hyperlinks
   - menhirLib: new functions
-      find_default_reduction
-      pop, top, equal, pop_many, get
-      force_reduction
-      input_needed
       feed (inspection API)
-      production numbers (production_index, find_production)
       current_state_number
     MenhirLib.Printers: incompatible type change of print_stack
     MenhirLib.ErrorReports: new module