Use 38400 as the line speed, this is the default footbridge console speed,
changing it confuses a remote serial line. Also updated in dot.hdprofile
Change the BLOCKSIZE to 1k, and the default EDITOR to ed.
Add standin shell funcs for dmesg and grep.
Only run sysinst if it's actually in the image.
This was tested using a custom INSTALL kernel. The current one is >4Mb
which the cats firmware can't currently boot. We need to decide what
needs to be removed from INSTALL.