- moves signal definition from "cli/js/process.ts" to "cli/js/signals.ts"
- removes "cli/js/dispatch.ts"
- removes "cli/js/types.ts"
- moves web specific utilities to "cli/js/web/util.ts"
- moves compiler implementation to "cli/js/compiler/" directory
- moves more APIs to "cli/js/web":
* "console.ts"
* "console_table.ts"
* "performance.ts"
* "timers.ts"
* "workers.ts"
- removes some dead code from "cli/js/"
