Gracefully handle jp2 images generated without -Clevels

Please pardon any mistakes I make in the reporting of this issue, but I clearly barely know what I am talking about.

We are getting errors in the syslog and nginx log like the following:

```
Jan 6 22:42:20 ___.us.a___.org php5-www-priv[4177]: Kakadu Core Error:
Jan 6 22:42:20 .org php5-www-priv[4177]: Attempting to access a non-existent resolution level within some
Jan 6 22:42:20 .org php5-www-priv[4177]: tile-component. Problem almost certainly caused by trying to discard more
Jan 6 22:42:20 .org php5-www-priv[4177]: resolution levels than the number of DWT levels used to compress a
Jan 6 22:42:20 .org php5-www-priv[4177]: tile-component.
Jan 6 22:42:20 .org php5-www-priv[4177]: pnmtojpeg: EOF / read error reading magic number
```

and:

`2015/12/29 16:29:22 [error] 30935#0: *23910069 FastCGI sent in stderr: "PHP Warning: BookReader Processing Error: unzip -p '/2/items/cu31924051987323/cu31924051987323_jp2.zip' 'cu31924051987323_jp2/cu31924051987323_0005.jp2' | /petabox/sw/bin/kdu_expand -no_seek -quiet -reduce 4 -rotate 0 -region {0.000000,0.000000},{1.000000,1.000000} -i /dev/stdin -o /tmp/stdout.bmp | (bmptopnm 2>/dev/null) | pnmtojpeg -quality 75 -- in /var/cache/petabox/petabox/www/datanode/BookReader/BookReaderImages.inc.php on line 453`

notes from h___ at archive dot org:

> "I.e., when making a jp2 from a bilevel source image (all pixels fully white or fully black), a certain option has to be specified while making the jp2 in order to be able to use the "-reduce" option when reading the jp2. That option has been specified for jp2s that we've made from bilevel sources since Feb 2011.
>
> In the case of the error Tim reports, the jp2s were provided to us (created by K..., during a scanning project at C...). Those jp2s were evidently created without using that special option, so the images can't be extracted from them at a reduced resolution, as BookReader attempts to do ("kdu_expand ... -reduce 4 ... ").
>
> I'm not sure what we can do, short of modifying BookReader (for which no one currently at the Archive knows the code) to check first whether an image file can be reduced, and if not, extract at full resolution and reduce as part of the pipeline of conversion commands (i.e., insert a call to "pnmscale" just before the call to "pnmtojpeg")."