(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

src/portuguese/IrregPorAbs.gf

@@ -1,6 +1,4 @@
 abstract IrregPorAbs = Cat ** {
   flags coding=utf8 ;
 
-  fun estar_V : V ;
-  fun fazer_V : V ;
 }