make the HTML output of the REST servlet JSON-compatible.

Some notes on my changes:

- I noticed that arrays were missing the opening and closing brackets so I added those
- it would have been easier to make the changes in pure CSS (see below) but then the characters can not be copied (really bad if you want a quick and dirty solution for getting a JSON object)
- since every tag can only contain one text string and multiple other tags, I was not able to separate the quotation marks from the links (for id fields)
- I removed a bit of copy which was used to output some info about an object. Mainly to make it JSON-compatible (and because all that info should be inside the object itself)
- I intentionally did not remove the reference to the (broken) Javascript file
- I also did not touch the CSS. Personally I would inline this so the page does not make requests to structr.org (but thats personal preference I guess)


# CSS Solution

```
/* insert a "," after every li */
li:after {
  content: ",";
}

/* remove the "," for the the last child of the li */
li:last-child:after {
  content: "";
}


.string:before {
  content: '"';
}
.string:after {
  content: '"';
}

a.id:before {
  content: '"';
}
a.id:after {
  content: '"';
}
```