[3.1.0] Further cleanup, making standalone work again

- Remove includes call in HTMLPurifier.auto.php
- Relax ConfigSchema treatment in generate-includes.php
- Clean up some empty comments (there are probably more)
- De-indent some extends
- class_exists() should now attempt to use autoload
- schema.ser is now a standalone file
- tests/index.php can be run from any directory

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@1540 48356398-32a2-884e-a903-53898d9a118a

maintenance/merge-library.php

@@ -145,6 +145,7 @@ $FS->rmdirr('standalone'); // ensure a clean copy
 // data files
 $FS->mkdirr('standalone/HTMLPurifier/DefinitionCache/Serializer');
 make_dir_standalone('HTMLPurifier/EntityLookup');
+make_file_standalone('HTMLPurifier/ConfigSchema/schema.ser');
 
 // non-standard inclusion setup
 make_dir_standalone('HTMLPurifier/Language');