Merge __init_env__.php into __init_script__.php

Summary: There are currently two files, but all scripts require both of them,
which is clearly silly. In the longer term I want to rewrite all of this init
stuff to be more structured (e.g., merge webroot/index.php and __init_script__
better) but this reduces the surface area of the ad-hoc "include files" API we
have now, at least.

Test Plan:
  - Grepped for __init_env__.php (no hits)
  - Ran a unit test (to test unit changes)
  - Ran a daemon (to test daemon changes)

Reviewers: jungejason, nh, tuomaspelkonen, aran

Reviewed By: jungejason

CC: aran, jungejason

Differential Revision: 976

scripts/sql/upgrade_schema.php

@@ -19,7 +19,6 @@
 
 $root = dirname(dirname(dirname(__FILE__)));
 require_once $root.'/scripts/__init_script__.php';
-require_once $root.'/scripts/__init_env__.php';
 
 phutil_require_module('phutil', 'console');
 phutil_require_module('phabricator', 'infrastructure/setup/sql');