Installing a new version does not remove old files under Program File (Windows)

[bertfrees]

Romain an I discovered this when debugging an installation issue on George's PC this week.

installer.nsi has got these lines:

DetailPrint "Removing old data..."
ReadEnvStr $0 APPDATA
IfFileExists "$0\DAISY Pipeline 2" +1 +2
rmDir /r "$0\DAISY Pipeline 2"

For some reason this does not work. @mccallum-sgd Do you understand what this code does? Any idea what could be the issue?

[bertfrees]

The lines above only remove the files under AppData. I added some lines to remove the files under Program Files as well.

[bertfrees]

PR: #158