Only copy original request headers when following redirects [fixes #4790]

When following a redirect, the client should not add NULL headers
from the follow_headers list that were not set on the original
request. This prevents problems when requesting URLs that
include an authorization signature calculated from the request URL
and headers.
Merge pull request #401 from acoulton/3.3/bug/4790-extra-headers-on-redirect-follow

Only copy original request headers when following redirects [fixes #4790]
Update license URLs in PHPDoc - Ref: #4821

Found links pointing to old location
of license instead of where they are
now at http://kohanaframework.org/license
Merge pull request #466 from randomecho/4821-update-license-links

Update license URLs in PHPDoc - Ref: #4821
Simplify Kohana::globals() test

This simplifies the `test_globals_removes_user_def_globals` test
to take advantage of PHPUnit's backupGlobals option which is on
by default. There's no need to backup globals.

In addition, changed to avoid directly assigning to $GLOBALS,
since it is not allowed in HHVM. See:
https://github.com/facebook/hhvm/blob/master/hphp/doc/inconsistencies#L127
Merge pull request #477 from jeffchan/fix-globals-test

Simplify Kohana::globals() test
Use `preg_replace_callback()` in `_ucwords()`

/e modifier is deprecated since PHP 5.4
Update Security.php
Update Cookie.php
Merge pull request #492 from sarciszewski/3.3/develop

Add Security::slow_equals and make use of it in Cookie::get and Security::check
Allow query-only links in HTML::anchor

Added tests for query-only and fragment-only links
Merge pull request #506 from enov/3.3/bug503/HTML-anchor-allow-query-only-links

bug #503: allow query-only links in HTML::anchor()
Fix for issue #496 - bad Request::url() docblock
Don't use classes from modules until all modules are successfully enabled
Split module initialisation functionality from Kohana::modules() into Kohana::init_modules()
Fix resending headers following redirect

Fixes failing test - all header keys are lowercase
internally so comparison was not working as expected
and the header values were not being properly copied
by array_intersect_assoc as that function compares
both key and value.
Merge pull request #525 from lenton/3.4/bugfix/module-classes-reliance

Don't use classes from modules until all modules are successfully enabled
since php 5.5.0 /e modifier is deprecated
Fix Arr::get for ArrayObject on HHVM - fixes HTTP_Header behaviour

HHVM 3.2.0 may emit a PHP Notice (Undefined Index) when calling
isset on an ArrayObject that maps the keys in some way - for example
the HTTP_Header object which converts all keys to lowercase - see
https://github.com/facebook/hhvm/issues/3437

Implemented a workaround in Arr::get to resolve breaking tests for
Kohana_Request_Client on HHVM.
Ensure Date::formatted_time always has expected timezone

Always re-assign the requested timezone in Date::formatted_time
- this will be a no-op if the timezone already matches, otherwise
 it will convert the time as required.

 It is not currently safe to make this a conditional call based on
 comparing the existing timezone name, because of
 facebook/hhvm#2302.