Three minor bug fixes: 1. When downloading metadata files, make sure we only download each file once; without this fix, "freebsd-update fetch" will fail the first time it is run if there have been no updates yet for the installed release. 2. If the FOO kernel is installed in /boot/kernel instead of /boot/FOO and the /boot/FOO directory does not exist, don't try to update /boot/FOO.  This is an issue only where an update involves adding a new kernel module. 3. When removing files and directories, operate in reverse lexographical order, in order to ensure that files are removed before the directory which contains them.
Three minor bug fixes:
1. When downloading metadata files, make sure we only download each
file once; without this fix, "freebsd-update fetch" will fail the first
time it is run if there have been no updates yet for the installed
release.
2. If the FOO kernel is installed in /boot/kernel instead of /boot/FOO
and the /boot/FOO directory does not exist, don't try to update
/boot/FOO.  This is an issue only where an update involves adding a new
kernel module.
3. When removing files and directories, operate in reverse
lexographical order, in order to ensure that files are removed before
the directory which contains them.

MFC after:	3 days

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase