Fixed broken links to php.net and redirecting pages to php.net

Let plugin add their own classes to list/table created with doku's renderer methods

Translation update (sk)

this hopefully helps with recent problems of spradically failing tests.

Clean up of mail text signature

upgraded jQuery to 2.2.3

Check if content really changed in the Editor, before popup a warning…

array splice operations are expensive. when many cells in a table row
are missing, the operation should be executed only once instead for each
missing cell.

Default only text string exists, via localized translation a wiki admin
can add his/her own (html) version.

Invalidate user session cache after profile data was changed (fix #1117)

Keep query params during redirect to headpage

Small fixes for file size changes

As discussed in Issue #1454 dokuwiki currently "forgets" additional
queryparams when redirecting from devel: to devel:start

Example:
https://www.dokuwiki.org/devel:?foo=bar
should result in
https://www.dokuwiki.org/devel:start?foo=bar
but actually results in
https://www.dokuwiki.org/devel:start

This commit fixes that behaviour.

Fixes #1454

Could improve failing test of #1589

Merge branch 'lang_update_18' of https://github.com/dokuwiki-translate/dokuwiki into dokuwiki-translate-lang_update_18

Conflicts:
	lib/plugins/authplain/lang/hr/lang.php
	lib/plugins/config/lang/hr/lang.php

Remoteapi getversions

Keep filter options in the extension manager

inline small images into the CSS by default

Improve RTL (Right-to-left) behaviour in media manager

Conflicts:
	lib/exe/xmlrpc.php

checkfunc is mainly replaced by doku_hasTextBeenModified, which is put
in  global scope to allow overriding by plugins.