Some items that needs to be done:

Parsing:
 - do not reparse the whole document when a <? or <script > or similar thing is
   added. Now the whole reparse is triggered if the parsed (invalid) area has a
   special block without end, like <? without ?> or <script> without </script>.
   This will speed up Quanta.
 - do not reparse the whole special area when something is changed inside.
   Reparse only the changed nodes. This will speed up Quanta.
 - do not reparse the whole file when a text is moved inside the document
   (cut&paste in one step, like when doing d&d). I don't have any idea how to do
   it... This will speed up Quanta.
 - parse the special areas correctly, even if there is a special area close string
    quoted inside the area (it should be ignored). Examples of wrongly parsed codes
   are:
   A: <? echo "?>" ?>
   B: <script language="JavaScript">
       <? echo "</script>" ?>
       </script>
   C: <? <? ?> sometext (?)

 - auto-creation of DTD Tags from a DTD definition

Structure tree:
 - do not delete and rebuild the structure tree when it's not necessary. Delete and rebuild
 only the changed nodes. This will speed up Quanta.

Plugins:
  - QXSLDBG
  - Kallery
  - config dialog rework

Misc:
 - WYSIWYG
 - remove unneeded header file dependencies
 - re-structure the files in the project. Now it's quite a mess.
 - fix the session restoration, especially if users still say that
   the current implementation is not acceptable

Bugs discovered:
 - slow editing even for XML (kde-features.xml)
 - autoclosing closes also single (unknown) tags
 - autoclosing does not always closes a tag
 - attribute tree is updated and redrew on every keypress
 - bug in plugins editor? "Invalid Output Window" errors after modifying the plugin.  