Cleans up after failed curl download

Signed-off-by: Juha Kallioinen <juha.kallioinen@jollamobile.com>
Retain current working directory when entering the SDK chroot.

Signed-off-by: Juha Kallioinen <juha.kallioinen@jollamobile.com>
Allow symlinks to be copied

Signed-off-by: David Greaves <david.greaves@jollamobile.com>
In the event the target isn't present it will be created

Signed-off-by: David Greaves <david.greaves@jollamobile.com>