Add an executable for condensing code
Introduce weights when adding types to avals
Clean up inheritance structure in infer.js
Adjust condense.js to new meaning of + syntax
Fix constraint that was created by plain obj literal
[emacs mode] Fix another fragment-construction bug
Fix bug in finding variable definitions in fragments
Reorganize files (scripts to lib/, desktop.js -> bin/tern)
Catch another accidental-capture case when renaming variables

Closes #20