this is a patch submission but fix in a different way

 - Setting any of the branch lengths to 0.0 results in divide by zero. Min value for the length setting is now 0.000001
 - Preset export failed with the change to the way that vector properties were stored. Now we just store a slice copy of the vector in the export.

* Added support for edge length measurement
* Updated API revision and Blender version
* Rearranged some things to make code clearer - it's still pretty cumbersome :-(.
* Also moved "Update selection" button to the very top.

Added full support for film back sensor size (2 new properties in ImportChan class - sensor_width and sensor_height)

- remove check if sensor width exists for chan files
- tag nuke chan files to be pep8
- remove unused import

from Paulo Dias (paxnubis)

moving Nuke *.chan io camera animation import/export scripts into trunk, this is a very simple foramt and nice to have with tracking release

[[Split portion of a mixed commit.]]

from ed gautier (edddy) 

Dear all.

Some large data classes (elements, atoms and sticks) use 

           __slots__

now.


Cheers,

Blendphys.

Moving PDB importer into trunk,

thanks to Clemens Barth for making all edits requested to have this in an acceptable quality level.

There are a few todo's still but at this point the script is better then the previous PDB importer in trink, so better to include this in the 2.61 release.

[[Split portion of a mixed commit.]]

removing this PDB importer in preparation to replace with a re-written one which supports more file types

Fixed Bug in Bolt Factory “remove doubles” function, which was introduced during indentation clean up.

indentation edits and copy pyrimid from contrib (where I had made some edits), removed so this wont happen again.

- Added a button for copying render settings from Blender render due to a bug involved if changing render engine from the render engine menu instead of the button
- Removed debug prints