[Exist-open] More changes

[Wolfgang M. <me...@if...>]

some more changes I made to the CVS version:

* following Michael's suggestion, match-tagging (highlighting) can now be 
independantly configured for attributes and elements. I also found out that 
version 0.9.1 did not allow to disable the highlighting of hits in attribute 
values (several if-statements were missing).

* pretty-printing and match-tagging is now turned off by default. The xmldb 
driver classes have been changed accordingly.

* I made several changes to the btree code while testing xupdate. As a 
positive side-effect, removing documents and - in particular - collections is 
much faster now.

Best regards,

Wolfgang