Instead of a dedicated function to toggle the TOC we now have a function
that allows to use this functionality everywhere. This will be used to
toggle the sidebar in the mobile view (in an upcoming patch).

Note, this required some changes to the CSS (to make it more generic).
The CSS is still located in the TOC sections but should probably be
moved into its own section instead.

Attention: Template authors need to adjust their CSS!

Original structure:
div.search_result >
  a.wikilink1 > span.search_cnt
  br
  div.search_snippet

New structure:
dl.search_results >
  dt > a.wikilink1
  dd

Attention: Template authors need to adjust their CSS!

Original structure:
div.toc >
  div#toc__header.tocheader.toctoggle > span#toc__toggle.toc_close|toc_open > span
  div#toc__inside > ul.toc > li.level1 > div.li > span.li > a.toc

New structure:
div#dw__toc.open|close >
  h3 > strong > span
  ul.toc > li.toc > div.li > a

Instead of three stylesheets for 'all', 'screen' and 'print' modes, they are all loaded into a single stylesheet by wrapping all screen styles in a "@media screen {}" and all print styles in a "@media print {}". The 'all' mode is not wrapped in anything.
Potential issues with existing CSS: If any of your screen or print CSS files already contain any "@media" syntax, the CSS will probably break. In that case please add any CSS with "@media" in it to the 'all' mode instead!

Also, the 'rtl' mode is hereby deprecated. Please just prefix any RTL styles within your normal CSS files with "[dir=rtl]". This also fixes that RTL styles cannot be added for 'all' or 'print' modes.

removed all browser-specific gradients as the recently (in 42ff6730) introduced svg makes them unnecessary

fixed performance issues with gradient in Firefox (which also added gradient support for IE9) (FS#2447)

* removed all occurrences of '-moz-linear-gradient'
* added SVG as fallback for Firefox, IE9 and other browsers to page background and buttons

This time PHP and libGD is used so it should work on Windows as well.
The image quality is much better this time and the active highlight
color is read directly from the template's style.ini

This makes it easier to modify or extend the icons in the sprite.
Just place the source files in the pagetools directory and run the build
script.

as discussed at https://github.com/splitbrain/dokuwiki/pull/82#r419699