Adjust CustomBiomes to also include its config.xml file

CustomBiomes has a config.xml file that is associated with the mod
itself, not the biome data.

This change has config.xml installed with the mod, *not* its data. This
provides compatibility with newer CustomBiomes releases.

This also updates some of the older CustomBiomes-Data-RSS packs to do the right thing as well.

Typical manifest of the new CustomBiomes install:

```
Custom Biomes version 1.6.8

== Files ==

GameData/CustomBiomes
GameData/CustomBiomes/biome.png
GameData/CustomBiomes/BiomeIcon.png
GameData/CustomBiomes/CustomBiomes.dll
GameData/CustomBiomes/License.txt
GameData/CustomBiomes/PluginData/CustomBiomes/config.xml
```

(Also, this reveals that new ckans cause `ckan show` to crash!)