* DB VERSION
* add only opens writable db on doc.sync()
* set/get title, author, tags as data or values (is this faster?)
* pdf thumbnails:
   "convert -thumbnail 500x -background white -alpha remove file.pdf[0] thumb.png"
   ([0] == pdf page)
* gtk gui, with pdf thumbs
* rework db/doc interface
   * doc is just directory and xapian_doc
   * db does write/index on sync

doc:
* add ability to remove source sid
* add ability to replace/remove file
* what to do with doc 'data' field:
  * snippet/summary (current)
  * data for fast retrieval?
  * bib abstract
  * custom annotations/notes
  * nothing

cli:
* utilize meta-data pulled from parser
* update should re-pull from existing source if available
* export should produce full mirror of xapers document structure

nci:
* custom keybindings
* customize helper commands
* how to test??
* add update/add commands
* customizable palette

sources:
* add 'hdl': http://handle.net/proxy.html

parser:
* extract metadata from pdfs
* better handle parse errors
* better pdf parser (native python: https://gist.github.com/pazz/5455090)
* parsers for other document types

?
* emacs UI (need json/sexp output)
* rename file when importing and copying into docdir?
* store bib data in different format (json instead of bibtex)?
* clear old indexed terms when importing new file/bib?
* vcs integration (git of root)?


BUGS
====

* capitalized prefixed terms are not searchable
  - dcc:T00000
  - key:HaEA2009a
