Add firmware-ralink to the package list.

Add support for the Belkin F6D4050, which is based on the RT2870
chipset, requiring the firmware-ralink package.
Use Blowfish for ssh encryption.

Blowfish is less processor intensive, and hence useful on
lower-specification terminals.
Add a simple Makefile.
Ignore various files.

The thinlinc packages come from Cendio. The remainder are the output
of building the image or converting the (meagre) documentation.