improve documentation
Merge branch 'experimental/multiple-versions-in-one-file' into refs/top-bases/experimental/php

* experimental/multiple-versions-in-one-file:
  improve documentation
Merge remote-tracking branch 'refs/remotes/gh/experimental/php' into HEAD

* refs/remotes/gh/experimental/php: (34 commits)
  updates, todo
  patch
  fix php-fpm-5.2 startup
  socket & service
  update php 5.2 for testing
  resurrect php 5.2. Need to run old code
  php 5.2 no parallel
  don't depend on syslog.target, stop tracing
  privatetmp
  nicer shorter php id only based on config, update php-fpm-5.3 to make it work with systemd
  start rewriting jobs as systemd
  php fpm daemons: allow setting PHPRC to php ini file so that xdebug works
  typo2
  typo
  php fix
  php new sources
  extra pool lines
  php adding ldap support
  allow extra lines
  php with derivation specific id, only provide system_fpm_config if sapi=fpm
  ...