envsetup.sh: explain _why_ there's an adb function in here.

    echo "can't find Android.mk"

}

# Ensure that we're always using the adb in the tree. This works around the fact

# that bash caches $PATH lookups, so if you use adb before lunching/building the

# one in your tree, you'll continue to get /usr/bin/adb or whatever even after

# you have the one from your current tree on your path. Historically this would

# cause confusion because glinux had adb in /usr/bin/ by default, though that

# doesn't appear to be the case on my rodete hosts; it is however still the case

# that my Mac has /usr/local/bin/adb installed by default and on the default

# path.

function adb() {

    local ADB=$(which adb)

    if [ -z "$ADB" ]; then