opencode setSlot (bootstrapping crash appears to be fixed).  also reorder the args to '==' when testing for nullness so that the null is first.
use the same syntax. property access -> closure env lookup trick in optimizations.coffee
stub out ES6 Map
add some tests for property lookups using different kinds of strings (ropes, dependent)
add a switch test using different types of strings.
ignore ejs.js.exe.stage3