Added a few RCS $Id$ tags.
# Note: I have avoided changing any .h files if the corresponding .c file
# had not already been changed as I am not sure if there are any legal
# issues here. So some extensions still have PHP 3 headers.
Draft 3 of IEEE 1003.1 200x, "2.2 The Compilation Environment"
All identifiers that begin with an underscore and either an uppercase
letter or another underscore are always reserved for any use by the
implementation.
