*8798* Fix TinyMCE cache file when a single OJS install hosts multiple journals...

... with different base url paths by adding the baseurl to the hash.
The current patch construction is relative, so perhaps `Request::BasePath` instead of `Request::BaseUrl`?

I chose `dirname($_SERVER["SCRIPT_NAME")` because this is what is used on 194 to construct the path:

```
	// Set base URL for where tinymce is loaded from
$buffer = "var tinyMCEPreInit={base:'" . dirname($_SERVER["SCRIPT_NAME"]) . "',suffix:''};";
```

We could refactor both to `Request::BasePath`, though I'm having a bit of confusion with that method's interaction with mod_rewrite.  c.f.: http://pkp.sfu.ca/bugzilla/show_bug.cgi?id=8797