- Removed SCCS rule from Makefile.am
- Made dummy rule in sql_yacc.yy to get rid of compiler warning about not used label.
Don't use maintainer mode with valgrind (as we don't want to initialize all variables)

config/ac-macros/maintainer.m4:
  Don't use maintainer mode with valgrind (as we don't want to initialize all variables)
  Force initialization of variables when using -Werror (To get rid of compiler warnings)
configure.in:
  Don't use maintainer mode with valgrind (as we don't want to initialize all variables)
sql/sql_yacc.yy:
  Made dummy rule in sql_yacc.yy to get rid of compiler warning about not used label.