Provide method to install from local media w/ no network access

[Steve Magoun]

I'd like to use jockey-text to install an appropriate driver from a pool on the filesystem without performing any network access. The use case is for customized versions of Ubuntu that need to install an appropriate proprietary driver from an on-disk pool on first boot (as part of oem-config, for example).

The reason I don't want network access is twofold:
1) There isn't guaranteed to be a network in this scenario
2) If there is a network, the overhead of apt can significantly lengthen the amount of time spent performing this stage. Since I can guarantee that the correct drivers are in an on-disk pool already, it is much faster to install directly from the pool.

export APT_SOURCES_LIST=/etc/apt/sources.list.d/foo.list
cat > $APT_SOURCES_LIST << EOF
deb file:/archive /
EOF
DETECT="$(jockey-text -l | cut -f 1 -d ' ')"
COUNT=$(echo "$DETECT" | grep -c foo)
if [ $COUNT -ne 0 ]; then
    echo "We should install the foo driver now!"
fi