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.

musl libc is complaining when <sys/poll.h> is used instead of <poll.h>
so change this.

This issue was reported for OpenWrt/LEDE where musl libc is the standard
C library instead of e.g. glibc, see the following link for the original PR:
https://github.com/openwrt/packages/pull/4263

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>
Signed-off-by: Michael Heimpold <mhei@heimpold.de>

--

v3: refined checks/fallback paths as suggested by @bukka

v2: rebased to resolve merge conflict in main/php_network.h

v1: initial PR

* PHP-7.0:
  Update php_network.h

```
In file included from /usr/local/include/php/main/php_network.h:124:0,
                 from /var/www/html/php-ext-handlersocketi-0.0.1/hs_response.c:3:
/usr/include/sys/poll.h:1:2: warning: #warning redirecting incorrect #include <sys/poll.h> to <poll.h> [-Wcpp]
 #warning redirecting incorrect #include <sys/poll.h> to <poll.h>
  ^
```