gpsd support

[Sylvain Munaut]

> I would like to suggest not making it a compile time option but a
> runtime option.  This would get rid of the #ifdefs and be much more
> elegant.  You simply configure in the config file if you want to use
> gpsd or the raw device...

Well, it would be annoying to _have_to_ install gpsd just to compile
cell_log ...

However, having gpsd shouldn't prevent device access if supported,
just add new functions.


A few comments on the patch itself:
 - I would split the rename and adding the gpsd in two patches
 - You erroneously activated TX in your patch ...
 - You add whitespaces at the end of some lines.

(it's always a good idea to reread the patch you post. :)


Cheers,

    Sylvain