ID_STATIC -> ID_PROTECTED

Rev: src/backend.cmod:1.229
Rev: src/builtin.cmod:1.217
Rev: src/errors.h:1.40
Rev: src/interpret_functions.h:1.208
Rev: src/iterators.cmod:1.70
Rev: src/language.yacc:1.440
Rev: src/object.c:1.299
Rev: src/pike_search.c:1.31
Rev: src/program.c:1.728
Rev: src/signal_handler.c:1.333
Rev: src/threads.c:1.259