add clear_env option to FPM config

This makes it possible to leave the envoronment as is on startup and
pass all the variables to the workers.
The default value of clear_env is "yes", preserving previous behaviour.
Patch by Paul Annesley.
Merge branch 'pull-request/598'

* pull-request/598:
  add clear_env option to FPM config
Merge branch 'PHP-5.6'

* PHP-5.6:
  fixed macro
  add clear_env option to FPM config
Merge branch 'PHP-5.6'
Merge branch 'PHP-5.6'

* PHP-5.6:
  Remove test case invalidated by openssl.cafile accessibility change
  Tolerate non-standard newlines when parsing stream CA files
  Remove openssl tests that shouldn't have survived last merge
  Add openssl.cafile ini check when loading cainfo
  Change openssl directives to PHP_INI_PERDIR
  Update openssl tests with new server/client test harness
  Add peer certificate verification on windows
Merge branch 'PHP-5.6'

* PHP-5.6:
  Prevent implicit function declaration when TLSEXT unavailable
Merge branch 'PHP-5.6'

* PHP-5.6:
  kick redundant include
Merge branch 'PHP-5.6'

* PHP-5.6:
  fix stdin reading in new openssl tests
Merge branch 'PHP-5.6'

* PHP-5.6:
  remove echo
Merge branch 'PHP-5.6'

* PHP-5.6:
  restored that test part in ext/openssl to enable notify/wait
Merge branch 'PHP-5.6'

* PHP-5.6:
  add NEWS block for 5.6.0 beta1
  add news entry
  add news entry
  add clear_env option to FPM config
  add clear_env option to FPM config
  Reduce test noise on cross Oracle client <-> server version tests. This fix is already in PHP 5.6+
  Reduce test noise in cross Oracle client <-> server version testing. This change is already in PHP 5.6+
Merge branch 'PHP-5.6'

* PHP-5.6:
  move the default encoding NEWS entry to alpha3, as it was pushed after beta2 was tagged
  rearrange the NEWS blocks a bit
Merge branch 'PHP-5.6'
Merge branch 'PHP-5.6'

* PHP-5.6:
  Deprecate CN_match in favor of peer_name in SSL contexts
Merge branch 'PHP-5.6'

* PHP-5.6:
  Remove cURL close policy related constants
Merge branch 'PHP-5.6'

* PHP-5.6:
  add missing NEWS entry
  add missing NEWS entry
  add missing NEWS entry
  add missing NEWS entry
  add missing NEWS entry
  add missing NEWS entry
Merge branch 'PHP-5.6'

* PHP-5.6:
  fix tests broken by 633f898f1520253d3530fe91fc82f68bca7c4627
Merge branch 'PHP-5.6'

* PHP-5.6:
  NEWS
  NEWS
  NEWS
  test for bug #66762
  Fixed Bug #66762 Segfault in mysqli_stmt::bind_result() when link closed
Merge branch 'PHP-5.6'

* PHP-5.6:
  update libs_version.txt
  update libs_version.txt
Merge branch 'PHP-5.6'

* PHP-5.6:
  typo spotted by Lajos Veres