* Made finddesc.lua execute commands using `sh -c 'command'`, which ensures that Unix-like shell is used instead of cmd.exe
* Made finddesc.lua avoid a situation where it would end up with a double '/' in `outpath`
* Redirect output of deleting the document to null to avoid pointless "No such file or directory" errors.

1. Made the Lua thing used be an optional variable, so it works for different Lua versions and locations

2. Made it work better with windows filesystems being weird with trailing dots.

it will also copy ../OC-Minitel/minitel.lua into ./service/minitel.lua if possible, for current development work