Merge pull request #1315 from tschneidereit/nat

Fix leftovers of insanely botched merge
Adds run-in-jsshell example
Merge pull request #1316 from yurydelendik/nat

Adds run-in-jsshell example
Remove SWC.
Remove old docs.
Delete stale files.
Remove more stale files.
Move opcode definition to bytecode.ts
Starting to port re-looper.
Moved most of looper, but no major cleanup.
Remove deps on estransform and escodegen. Using a simpler AST now.
Finished up porting backend.js.
Fix shell unit testing script