python script extension

[Bertalan Fodor]

Hello,

I'm wondering if it is intentional that lilypond-book.py became 
lilypond-book and convert-ly.py became convert-ly in the Windows version 
of 10.0-2. This is important for me, because for running these commands 
from LilyPondTool I should know this information. Because if I change 
the code again, I would like to know, if this will change again.

Bert