added things to output DOCTYPE to make IE operate not in quirks mode.

reorganized the docbook zip / unzip versions into a new folder at the same
level as lib, called docbook.
  - changed unzip to only unzip the first time, skip the rest of the time
  - changed xml-catalog.xml to point to new location
  
treatment of images:
  - leave as is: put all under images


  - start in src/docbook/uima/arbitrary-structure/xxx.xml
                         |_____ docbook.dir_____|
  
    images:                                     |___ filesets___|
    css:                                        |___ filepath___|
                           
                         |------docbook.dir-----|                         
  -               target/uima/arbitrary-structure/html/xxx.html etc
                                                 /htmlsingle
                                                 /pdf
    images:                                      |___ filesets___|
     css:                                        |___ filepath___|
                                                 
images and css are shared among both html and htmlsingle.
images are incorporated into pdf
image refs are written as ../filepath