Translation update (pt)

This makes sure the provided extension ID is a valid id before
initializing it in the extension manager.

No need to check those seperately. The correct order should be ensured
already.

Update html.php

$regex initialization added to clearify that it is passed by reference and filled from subroutines

When a page is marked as hidden (through the hidepages option) it should
not be indexed by search engines.

Translation update (eu)

Translation update (eu)

the new version of the validator is static. But it makes sense to use a
single point of entry anyway, so instead of adjusting the use of the new
class, prefer the function.

Various plugins access the form members directly currently.

Adjusted pattern for matching media links to properly handle a single '}' in the link text. Fixes #1587.

Added green and red text color styles for geshi. Improves look of highlighted code for language diff. Fixes #900.

The internal lang and localized variables of a plugin are no longer
accessible from the outside. This adds a proper setter and also fixes
the type hinting in the config plugin.

If an entry in the loop at `_tpl_metaheaders_action` has no content, skip this entry.

There are still some left in the DifferenceEngine code

this fixes another problem with our tests and phpunit 6.1

This fixes a problem with those tests in the most recent version of
phpunit. I thought it was caused by the use of the deprecated var
keyword, but some other weirdness was going on. This way it's more
proper anyway.