various Lilypond 2.9 Win-uninstaller problems

[Uwe Stöhr]

Hello Lilyponders,

I tested the latest Lilypond 2.9.16 for Windows and found out that it is 
not correctly uninstalled. After uninstalling it the following folders 
remain:

\usr\etc
\usr\lib

and its subfolders. The installation directory should completely be removed.

The following registry entries remains:

- HKCU\Applications\lilypond-windows.exe
  HKLM\Applications\lilypond-windows.exe
  and its subfolders

- The Start menu entry for Lilypond under HKCU

- the file extension ".ly" is kept registered in HKCU

Please remove these entries when uninstalling Lilypond, especially the 
kept file extension may later cause problems.

Lilypond also left some other registry entries in python registry 
settings, please also have a look of what can be removed there.
To assure that you took care of all entries search the whole registry 
after you uninstalled Lilypond.

thanks and regards
Uwe