generate three vista plus (mac) type buttons

This is an adaption of a script that I found (not sure where now but possible to re-find by searching on google). The name under the registration was Lucas Pettett so I guess it was his.
Originally it took some colours and text and produced a vista style button with a gradient dark part and light part horizontally divided. The corners were rounded and it had a border.
I have added the following things (so I can quickly create buttons for some of the applications I am working on):

1. horizontal edge has rounded corners and feathered
2. produces three versions:
   • grey - inactive form
   • normal button
   • mouse hover form (i.e. with the blue led shining through)
3. it's possible to pick up a vector/path type svg file (you can save a path as this by right clicking on the path in the dockable dialogue then choosing export). This will then be scaled to fit your button (so you will get distortion if they are mismatched shapes.)

I'm not a script-fu programmer so most of this is trial and error and would probably benefit from some expert scrutiny.
The GIMP I'm using is 2.6 on windows so I don't know if it works elsewhere.
(examples attached below)