Fix the return type and remove unneeded casts.
Add a number of more precise types and remove unneeded casts.
Fix nullablility in a number of places.
And add a few unrelated clarifying comments.
Merge pull request #376 from vandenoever/typed

Make all webodf.js 100% typed.
Remove dependencies that depend on other dependencies from manifest.json.
Create a dependency graph from manifest.json.
This is created at every run of the build system.
Do not exit before all files are written.
small edit to graph: interfaces are now always shown.
Add colors to the graph.