The $Id$ keywords were used in Subversion where they can be substituted
with filename, last revision number change, last changed date, and last
user who changed it.

In Git this functionality is different and can be done with Git attribute
ident. These need to be defined manually for each file in the
.gitattributes file and are afterwards replaced with 40-character
hexadecimal blob object name which is based only on the particular file
contents.

This patch simplifies handling of $Id$ keywords by removing them since
they are not used anymore.

If the same php_value/php_flag is present in httpd.conf and .htaccess,
the key is potentially shared between threads. Unfortunately we can't
intern these keys using the current mechanism, because the MPM is setup
before the SAPI module setup is even started. A more elegant way were
to implement a kind of string pool for the thread safe Apache SAPI
config directives with the mechanism similar to what is done for the
SAPI setup now, but doing a separate management.

* PHP-5.6:
  Happy new year (Update copyright to 2016)