Broken, disabled or failing unit tests are all fixed now.

Due to additional changes in the mesh verification, TRInDataStream had to be altered to always give an output if it's valid, even if that output is 0 bytes long. All this together fixes #50.
Fix loading of objects that can't be loaded.

If an object can't be loaded, the code now correctly reports the error,
tears down structures that were created, and removes the object again,
making it leave the selection if it was in it. The previous solution
sort of worked, but relied very much on precise timings of things,
while this should work no matter what order the invocation events come
in.
Fixed bug that made it impossible to remove items from the selection if the selection is items.

Honestly, how did this ever work to begin with?
Fixed various issues, including previous fixes.
Releasing new beta version.
Fix incorrect texture coordinates with OBJ export.
Release new beta version.
Fix observing to work in light of editors which delete and recreate the file on saving.
Fixed several issues related to exporting.

First of all, don't export hidden objects; assume the user hid them for a reason. Similarly, no reason to export items that cannot be rendered. Also, sometimes incorrect groups were used due to incorrect checking whether a match was valid.
Fixes #57.

Apparently setting the primitive value for the item relationship in the ItemMesh screwed something up. As a result, the meshes were empty by deletion time, meaning they wouldn't delete their textures or render parameters (because they didn't have references to them anymore)… but the textures and render parameters still had dangling references to the meshes. That resulted in multiple validation errors, as Core Data puts it.

To make something like this easier to debug in the future, the errors in this case are now logged. Also, bones are now deleted when the last item referring to them is gone. I first assumed that this was the problem. It apparently wasn't, but it's still much cleaner like this.
Published new beta version.
Fixed incorrect download URL for beta 4
Fixes #60.

This sets up a global notification for changed textures. All views observe this notification and redraw themselves when the texture has changed. This is not exactly the cleanest possible way to set this up, but it works okay. In the long term, the texture probably needs some way to inform its users of any changes (in particular renames), which could then be used for the redraw notification.
Fixes #59. At least I hope. It's hard to reproduce.

I was already handling app deactivated events, I just didn't send the right mask. So for future reference: It's NSAppKitDefined.
Fixes #61
Checks for locked cameras now happen only where the camera is to be updated, but they happen consistently there.
Change string to be more in line with other german-language software.
Fixed incorrect directions for moving objects with arrow keys.
Fixes #63 in an ugly way.

The comment says it all.
Released version 0.2 (final)
Fixing incorrect download URL.