Fix for update messages never completely going away

Corrected compression for ++ and -- operator. Partially fixes #897.

preserve comments in less if 'compress' config disabled

Otherwise comments are never visible in css.php

The existing logic for messages.txt requires some valid update
response (ending in %) to the messages update check before it clears
the current messages.

However update.dokuwiki.org appears to return an empty string response
if everything is up to date. (ie http://update.dokuwiki.org/check/46.1 )

As a result if there are update messages in messages.txt they don't
automatically go away after updating to the current version. The only
time they change is when a newer release comes out. The upgrade plugin
has logic in it to force a re-download of messages.txt, but currently
this just re-downloads the old update messages.

This change explicitly allows for "" as a valid "no messages"
indicator (distinct from false, which is the HTTP error indicator.)

Translation update (ko)

Fix for issues #877 & #885 related to a bug in PCRE 6.6

Since Chrome 37, they send differen accept encodings for POST and GET
requests which will break BrowserUID checks as reported in
cosmocode/dokuwiki-plugin-oauth/issues/3

See https://code.google.com/p/chromium/issues/detail?id=410559 for
official bug report at Google

Fix broken format string

extend lang file cascade, so users can override some lang strings

 date_at support 

Update text above searchresults, when only read-acl FS#2697

* bug865:
  work around missing gzopen on certain systems #865

remove config option

Conflicts:
	inc/lang/hr/searchpage.txt
	inc/lang/ko/searchpage.txt

different types
unused vars
PHPDocs

Conflicts:
	inc/plugin.php

Added support for external video and audio files

added filter method to INPUT class

clean user credentials from control chars

Last Update Date info of extension fix

Translation update (zh)