because config.status may later need this file (if it does not find it
it won't incorporate dependencies of errmsg.sys in sql/share/Makefile) (thx Serg).
In sql/share/Makefile.am using "all:" leads to double-"all:" in Makefile (thx Konstantin).



sql/share/Makefile.am:
  using "all:" leads to double-"all:" in Makefile (counting the auto-generated);
  all-local is the standard way to add something to all: (thanks Konstantin)
configure.in:
  Don't remove $AVAILABLE_LANGUAGES_ERRORS_RULES at end of configure.in
  because config.status may later need this file (if it does not find it
  it won't incorporate dependencies of errmsg.sys in sql/share/Makefile :( )