deprecate the static keyword * octave.gperf: Use PERSISTENT as the token for "static" and "persistent" but use separate static_kw and persistent_kw values so we can distinguish them. * lex.ll (is_keyword_token): Handle static_kw and persistent_kw separately. Generate deprecated keyword warning for static_kw. * oct-parse.cc: Use PERSISTENT token instead of STATIC. * pt-decl.h, pt-decl.cc (tree_persistent_command): Rename from tree_static_command. Change all uses. * pt-walk.h (tree_walker::visit_persistent_command): Rename from visit_static_command. Change all derived classes. * NEWS: note that static has been deprecated.