More tools, mostly to handle org-mode.

- New (inclomplete) sane-filename
- org-export-*: Removed overriding org-export header levels to hard 3
- Added scripts to annotate org-extracted source with line numbers
- Added org-babel-tangle: Untangle org-babel files from the command line
- Adding ORG->UTF8-Exporter for the command line
- Added: model-to-document: Ad-hoc reformat a model as org outline into something more
  printable.
- New: orx: Tools and configurations to work with org mode.
- Added: Some installation rules (symlinks in $HOME)