This commit does major refactor of "Worker" and "WebWorker",
in order to decouple them from "ProgramState" and "Flags".
The main points of interest are "create_main_worker()" and
"create_web_worker_callback()" functions which are responsible
for creating "Worker" and "WebWorker" in CLI context.
As a result it is now possible to factor out common "runtime"
functionality into a separate crate.
- Fixes cargo publish on deno_typescript, deno_cli_snapshots, and
deno_cli.
- Combines cli_snapshots and js into one directory.
- Extracts TS version at compile time rather than runtime
- Bumps version awkwardly - it was necessary to test end-to-end
publishing. Sorry.
- Adds git submodule deno_typescript/typescript
