mix pagenames and namespaces when sorting

As discussed in https://github.com/splitbrain/dokuwiki-plugin-dw2pdf/pull/399#issuecomment-624030852

properly sort pagenames by namespace. fixes #308

This ensures pages within the same namespace are put together, with the
start page being alwas first.

Make default replacement preventable

Add replacement event

Lets other plugins substitute their own placeholders in all parts of the template

Update action.php to add watermark option

Add option &watermark=<watermark> to url to watermark the pdf.

Remove redundant mapping in namespace filter

Filter namespace: exclude given ids

Change Google Infographics API to quickchart.io

The Google Infographics API was deprecated in 2012 and shut down on March 18, 2019. More information at https://developers.google.com/chart/infographi

Change Google Infographics API to quickchart.io

The Google Infographics API was deprecated in 2012 and shut down on March 18, 2019. More information at https://developers.google.com/chart/infographics/

show more ...

fix: adjust to changed style.ini handling (backwards compatible)

With the upcoming Greebo release of DokuWiki, the method css_styleini()
is no longer available in the global namespace. Its functiona

fix: adjust to changed style.ini handling (backwards compatible)

With the upcoming Greebo release of DokuWiki, the method css_styleini()
is no longer available in the global namespace. Its functionality can be
accessed via the new StyleUtils class.

show more ...

fix: don't include print styles if pdf.less exists

use destructor for deleting one-time cache file

ACTION_ACT_PREPROCESS event ignores returned value

replace ACT by event data

fix exit format for bookcreator
move preventDefault after change action (show).

msg if article not exist

show export button only if enabled and if article exists

Merge pull request #300 from cosmocode/removeOldRevCache

Export old revisions - no cache

Merge pull request #291 from cosmocode/fixPageSorting

fix: sort numbers after namespace separators with book_order=pagename

fix: do not backup $ID twice

$ID is already backed up in the new p_wiki_dw2pdf, hence it is no longer
necessary to do so in the outer loop.

include all.css after screen.css and add less files

Merge pull request #297 from LarsGit223/master

Code cleanup: replaced references to $ACT with $event->data on processing event ACTION_ACT_PREPROCESS

Merge pull request #301 from cosmocode/addOutputParameter

Allow overwriting the output configuration option

added two more placeholders

refactor: use 2nd paramater of INPUT->str function

refactor: delete dead code

This code is no longer in use since f00df45e96661cc2890b04059edadef10a345a50

fix: delete the temporary file created for old revisions