(Por) several minor updates (#49)

* fix linearization of either/or

* (Por) minor updates
- correction in Lexicon
- documentation in Morpho
- rm variants from Structural

* (Por) correct references to extinct opers

* (Por) rm Spa remnants

* (Abs) rm reference to Extra in Structural -- use Extend instead

* (Por) ExtendPor
- use Extend instead of Extra in All
- use Extend funs in Extra whenever possible

* trigger CI

* (Por) Diff
- sort opers
- rm old commented code
- tidy things up
- no semantic changes

* (Por) add IrregBesch module with verbs using Besch paradigms
- Besch :
  - use hack to prevent runtime failure with glue in in vars output
  - rm paradigm numbers
- add IrregBeschPor, verbs that use only bescherelle paradigms
  - use them in Construction, Structural, Idiom, Extra
- Diff and Paradigms had (almost) the same oper (verboV/verbBeschH),
  so combine them into one and use it

* (Por) update functions to use new Irreg suffix and resolve name conflicts

src/portuguese/AllPorAbs.gf

@@ -1,5 +1,5 @@
-abstract AllPorAbs = 
+abstract AllPorAbs =
   Lang,
   IrregPorAbs,
-  ExtraPorAbs
+  Extend
   ** {} ;