fixed mac addr bug in client.c

There was an issue when not enough of the mac address for the ipv6
tunnel client was being used when identifying itself to the server. That
has been remedied.
scp extra fix for components with paths

If you want to build an app in a different directory you can specify the
COMPONENT with a relative path. However, this broke the scp install
extra. By specifying just to use the filename with the scp call this is
fixed.
updated TUN

1. No longer uses brconfig.ini. Now uses whatever the set address is at
runtime to configure the tun interface.

2. Can now change the TUN device name. TunP calls TunName to get the
name of the TUN, which can be changed in a app specific manner.
configure tunname for borderrouter

Border Router uses -i flag on command line to set tun name.
border router uses brconfig.ini to set its ip