[DONTMERGE - WIP] First attempt to create DocBook 5 MAIN

[tomschr]

• Add chunker.xsl from DocBook XSL
• Create map-to-db5MAIN.xsl to create DocBook5 output for MAIN file
• Implement previous stylesheet in ditatodocbook.sh script

[ghost]

I've had a look at the new map-to-db5MAIN file.

• I diffed between map-to-MAIN and map-to-db5MAIN (see 568fa54085f26924cfc37f76dcd453662ac4009a). Getting a 600-line diff for a 250-line file is ... unexpected. Most of the diffed lines are (unwanted) whitespace changes.
• Your reworking currently partially destroys the features to remove/replace files at the top level. To make this work properly, you would need to copy/paste the relevant parts of normal-mode templates into the collect.files templates.
• It is also incomplete, there is still an xsl:message for content that needs to go into includes at the end left.

This is all stuff that had already been working.

If this is just about seeing error and warning messages on the command line, it seems to me that there are easier ways to get those (like just outputting the messages caught in includes after the xsltproc run). That may not be proper-est way to go about this but it would be quick.

[ghost]

Hm, there still seem to be a few issues here that I didn't figure out:

• we're somehow writing the DB5 namespaces in lots of elements, not just the root element
• daps xmlformat does not run, the error is ERROR: Failed to get filelist for ROOTID ""
• there is still an namespace-free xpath looking for @linkend

Also, I have moved your map/bookmap commit onto https://github.com/sknorr/dietrich/tree/f/map-to-bookmap