acceptChanges frontend: Cross-platform Java frontend

In order to provide cross-platform support, I suggest
that a Java-based frontend should be developed.

The core functionality should include:

- open / save / save as ... file actions
- filtering of trackchanges:
o process only commands with certain initials:
this enables that a user can accept / reject
changes of himself/herself or of another
dedicated user
o process only a selection of commands:
for example: only \note and \annote commands
should be processed
- a button to accept all changes/adds/removes
- a button to reject all changes/adds/removes
- a button to accept the selected changes/adds/removes
- a button to reject the selected changes/adds/removes
- a button to remove all notes/annotes
- a button to remove the selected notes/annotes

In order to select changes quick and easy, the entire
document has to be presented and changes must be
highlighted.

My idea was to add a checkbox to each change command
such that the user can go over the document and simply
select the changes with the mouse.
An alternative to a checkbox would be to present
changes like links on a webpage: the user can directly
click on the text to select / deselect it. Once
selected the text must change color.

The optimum presentation would be that the frontend
interacts with a DVI viewer! The user could go over the
DVI document, click on a marked change and the GUI
would jump to the appropriate position in the
source.... but that's maybe too much ...