HDX: load wpt files multiple times bug

[jteresco]

If you load a WPT file, then load another, the route is OK, but the "raw file contents" area then has the contents of both files.

[jteresco]

Need to be considering this as we test and debug @mdagsjr's UI redesign.

[yakra]

I haven't looked under the hood here, but this looks like a case of a Javascript foo.innerHTML += "yadda yadda" that should instead be foo.innerHTML = "yadda yadda"

[jteresco]

This was a little insidious, and affected all file types. It's essentially what @yakra suggested, but appending the entire table to the contents of the div for the loaded data (the "contents_table"). Fix forthcoming for the hdxt version, will get into the production version later this month.