cleanups and fixes:
- remove parser from pub namespace, import directly
- transpile/repr tests (aka, in target lang)
- "transpile" => "compile"
- refactor model creation/write/update into library routine
- validate incomplete identifiers (?)
    => aka, check that identifiers match component list..
    => involves moving identifiers() to parser?

- finish rebalance/resolve/rephrase for {x}
    => needs tests!

- odex-based ODE solver demo
    => http://blog.littleredcomputer.net/math/odex/js/2016/04/03/lotka-volterra.html

webface:
- move create form to sandbox page?
- more descriptive edit page (link to modelica spec?)
- better wiki editor: show parse errors, syntax highlight, show line nums
- minimum viable library and daemon/API for accessing db of models
    => cross-model type validation
    => versioning/tagging allowing editing of dep tree
    => versioned transpiling
    => federation/merging

later:
- basic travis setup
- basic generation of python/julia code from model
- LICENSE (AGPL, CC0 for generated code)
- look at libsyntax for (maybe) rust idiomatic ways to do AST stuff
- more complete modelica support ("import" large files into multiple linked models)
- error pretty printer isn't great
- refactor Debug and Display for AST (?)
- logging (slog? or default to 'INFO')
- testing framework with "raises" and "assert_gt"
- rename to "modell-dinge"?
- elm explorer?
- #![deny(missing_docs)]
- tangle demo

design/future:
- https://siciarz.net/24-days-rust-git2/
- a more fortress-like syntax