This should reduce the complexity of the function

Fix more PHP Notices

This fixes the PHP Notice when $headers['Content-Type'] is unset. It
also allows for easier extension later, e.g. adding handling for a JSON
content-type.

If a key is not set, a PHP Notice is triggered. While these are
currently suppressed, this is still a code smell.

This function might be called by an plugin with an array that has only
string keys and hence no key 0. This would trigger an PHP Notice when
trying to get the first key's level.

If an config value is not set in the input lines, initialize it as empty
string to prevent PHP Notices complaining about $line[1] being not set.

A PHP Notice occurred when $url didn't contain a '?'.

Prevent duplicate "selected" attributes in option tag in Form.php (DropdownElement)

Corrected external link syntax, now requires preceding whitespace.

hopefully this will help with figuring out why our HTTP tests sometimes
fail on travis.

Update check supports HTTPS (without fallback)

If SSL is not supported, a HTTP request will be made. In the log the request type will be indicated, but on the frontend no additional message would be shown (I think it's better to notify admins about non-SSL situations, but currently when this fetch encounter error, no error message will be shown, so it's better not to add any warning).

* 'master-fix-windows' of git://github.com/yurii-github/wiki:
  response on review
  response on review
  cleaning after better understanding of the surroundings
  back slashes in @import
  cleaning
  fix tests on windows

Action Dispatch Refactoring

* 'fix-2087' of git://github.com/phy25/dokuwiki:
  Fix p_set_metadata damaging contributors with numeric ID
  Add tests for array_replace part of set_metadata

just to be sure, we're not breaking something simple here.

* 'issue829' of git://github.com/LarsGit223/dokuwiki:
  Corrected internal link pattern to properly handle included square brackets. Fixes #829.

bugfix: empty string is valid for numericopt

Fix rendering null $language going to GeSHi (fixes #2088)

Fix RSS syntax XSS bug (#2081)

Fix sanitation of $language for code highlighting (fixes #2080)

Translation update (fr)

Removed progressbar from searchform

There was a bug that the empty string was considered to be invalid if
also a max or min value was defined for a config field of type
numericopt.