Clean and reorganise list generator code
Move cmd processing to task stylesheet
Use URI in Reference path #1544
Change gen-list to process absolute paths

Instead of storing file references as relative paths, keep everything
absolute until serialization.
Clean error messages
Clean preprocessing
Use URI instead of File in generating source listings #1762
Fix obsolete content from documentation

Remove mention to obsolete gen-list-without-flagging Ant target.
Normalize relative paths in mapref #1683
Clean maplink stylesheet
Clean maplink XSLT
Use tunnel parameters in maplink XSLT
Use () instead of #none# in maplink XSLT
Fix sibling links in map link #1683
Update library dependencies #1791
Upgrade to 2.0 release
Fix issues reported by IntelliJ IDEA
Remove NP plug-in #1512

Remove NP plug-in code, as most of the plug-in functionality has been
migrated to default preprocessing plug-in.
Merge branch 'develop' into feature/ot2_release_notes

* develop:
  Remove NP plug-in #1512
  Fix issues reported by IntelliJ IDEA
  Upgrade to 2.0 release
  Update library dependencies #1791
  Fix sibling links in map link #1683
  Use () instead of #none# in maplink XSLT
  Use tunnel parameters in maplink XSLT
  Clean maplink XSLT
  Clean maplink stylesheet
  Normalize relative paths in mapref #1683
  Fix obsolete content from documentation
  Use URI instead of File in generating source listings #1762
  Clean preprocessing
  Clean error messages
  Change gen-list to process absolute paths
  Use URI in Reference path #1544
  Move cmd processing to task stylesheet
  Clean and reorganise list generator code

Conflicts:
	src/main/docsrc/readme/changes/rel2.0.xml (manually resolved)