phpfpm currently uses `readFile` to read the php.ini file from the
phpPackage. This causes php to be build at evaluation time.
This eliminates the use of readFile and builds the php.ini at build
time.
PHP FPM will now notify systemd when it's done initializing and ready to
serve requests.
Additionally ```systemctl status phpfpm``` will now show statistics such
as:
```
Status: "Processes active: 0, idle: 8, Requests: 0, slow: 0, Traffic: 0req/sec"
```
From @fpletz: Keep poolConfigs option for backwards-compatibility.
The original commit 6b3f5b5a42 was previously
reverted by c7860cae1a but the issues were
resolved.
This reverts commit 6b3f5b5a42 because it
introduced a non-backwards compatible change in the phpfpm interface,
without really needing to. The new interface, if needed, can be re-added
alongside the old interface.
Commit 98e419c0e2 ("tt-rss service: init at 16.3")
depends on the new interface, so this commit updates the tt-rss service
to work with the old services.phpfpm.poolConfigs interface.