Replace existing autoloader with Composer-supplied

- Move Friendica namespace to `src`
- Move required `ezyang/htmlpurifier` to vendor
- Remove existing static autoloader
- Change boot.php reference to the autoloader

vendor/ezyang/htmlpurifier/library/HTMLPurifier/Printer/ConfigForm.css

@@ -0,0 +1,10 @@
+
+.hp-config {}
+
+.hp-config tbody th {text-align:right; padding-right:0.5em;}
+.hp-config thead, .hp-config .namespace {background:#3C578C; color:#FFF;}
+.hp-config .namespace th {text-align:center;}
+.hp-config .verbose {display:none;}
+.hp-config .controls {text-align:center;}
+
+/* vim: et sw=4 sts=4 */