Add a few more known NBT extensions to the file pattern for directory enumeration.  Closes #21.  File-based open can already handle all extensions, from #31.
Add a few more known NBT extensions to the file pattern for directory enumeration.  Closes #21.  File-based open can already handle all extensions, from #31.

Askirkela/NBTExplorer,jaquadro/NBTExplorer