Changed `URL.port` implementation to match [WHATWG
specifications](https://url.spec.whatwg.org/#port-state).
This PR matches the behaviour of other browsers:
1. a `TypeError` must be thrown when passing an URL with an invalid
port to the constructor.
2. When setting an invalid port, using property setter, I haven't found
what should happen in this case, so I mimic **Firefox** & **Node**
behaviour. If an invalid port is set, it will use the previous value.
**Chrome** sets the value to `'0'` if an invalid port is set. I prefer
to keep the previous valid value. (I can use Chrome's behaviour if you
think it's better, it's a simple value change)
```
url.port = '3000'; // valid
url.port = 'deno'; // invalid
assertEquals(url.port, '3000');
```
3. If the port value equals the current protocol default port value,
`port` will be an empty string.
Refactors Event and EventTarget so that they better encapsulate their
non-public data as well as are more forward compatible with things like
DOM Nodes.
Moves `dom_types.ts` -> `dom_types.d.ts` which was always the intention,
it was a legacy of when we used to build the types from the code and the
limitations of the compiler. There was a lot of cruft in `dom_types`
which shouldn't have been there, and mis-alignment to the DOM standards.
This generally has been eliminated, though we still have some minor
differences from the DOM (like the removal of some deprecated
methods/properties).
Adds `DOMException`. Strictly it shouldn't inherit from `Error`, but
most browsers provide a stack trace when one is thrown, so the behaviour
in Deno actually better matches the browser.
`Event` still doesn't log to console like it does in the browser. I
wanted to get this raised and that could be an enhancement later on (it
currently doesn't either).
- 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/"
Following JS ops were moved to separate files in cli/js/ops directory:
- compiler
- dispatch_json
- dispatch_minimal
- errors
- fetch
- fs_events
- os
- random
- repl
- resources
- runtime_compiler
- runtime
- tty
