[patch 1/9]#2 Rename `enum target_signal' to target_signal_t

[Joel Brobecker]

> These were the reasons for the typedef but I do not mind and I can
> monkey-patch whatever gets agreed upon and be done with this part which
> accidentally became a code cleanup only patch.

I'm not against the typedef at all :). I was just thinking that
perhaps we could leave the enum alone as one component of the struct
(be it typedef'ed).

-- 
Joel