Move images + Create page Donate, fix Home (add button Home) + Add footer (donate)

Moved images from doc/images to www/images since they are backend specific, and
need not be sitted beside the actual documentation (the 'NOTE' icon might
not be taken from the same place when rendered to a PDF later).

That way, we'll be able to use those icons elsewhere on the website, without
fetching them from the repository. They aren't going to be updated, also,
and thus don't need versioning very much.

www/header.php

@@ -10,4 +10,13 @@
 <div id="page_wrapper">
 <div id="header">
   <a href="."><img src="images/logoSFLphone<?= ($module == 'home' ? '512x149' : '312x91') ?>.png" /></a>
+
+
+<?php if ($module != 'home') { ?>
+<div id="homebutton">
+  <a href="index.php"><img src="images/home.png" alt="Home" /></a>
+</div>
+<?php } ?>
+
+
 </div>
\ No newline at end of file