QA: $W_UNATTENDED_*

[Kreyren]

winetricks is using variables alike: $W_UNATTENDED_SLASH_QUIET that are expanting in /quiet to be recognized by wine where using `"$W_UNATTENDED_SLASH_QUIET" doesn't work -> Make a test

# Valid
"$WINE" "$W_CACHE/$W_PACKAGE/$file1" $W_UNATTENDED_SLASH_QUIET
# Valid 
"$WINE" "$W_CACHE/$W_PACKAGE/$file1" \quiet
# Invalid
"$WINE" "$W_CACHE/$W_PACKAGE/$file1" $W_UNATTENDED_SLASH_QUIET"
# Valid
"$WINE" "$W_CACHE/$W_PACKAGE/IE8-WindowsXP-x86-ENU.exe $W_UNATTENDED_SLASH_QUIET"
# Invalid
"$WINE" "$W_CACHE/$W_PACKAGE/IE8-WindowsXP-x86-ENU.exe \quiet"
# Invalid
"$WINE" "$W_CACHE/$W_PACKAGE/IE8-WindowsXP-x86-ENU.exe \\quiet"