doxygen and rebranding update

[Pete Batard]

As mentioned earlier, if you look in the git repo, you'll see that I 
just pushed 2 patches related to libusb -> libusbx rebranding. These are 
mostly aimed at having doxygen mention libusbx rather than libusb.

The first patch [1] is fairly heavy, but only impacts comments. While I 
was at it, I updated the headers, removed unnecessary trailing LFs, 
removed some obsolete info and switched all the copyright signs to UTF-8 
(it's 2012 for crying out loud! If you use an app that can't handle 
UTF-8, ditch it!). If we ever find that people complain because of the 
lack of a BOM, I don't mind adding one, but for now, and unless 
specified otherwise, any text file is expected to be BOM-less UTF-8. 
This of course also applies to all of our sources.

Second patch [2] is an update of doxygen, with the aim of now being able 
of providing this to our users:

http://libusbx.sourceforge.net/api-1.0/

Hopefully, I've replaced all the naked mentions of libusb into libusbx, 
but if you still see  I added a logo, since I had one at hand, as well 
as a tagline, since the doxygen config provides an entry for one (which 
is currently worth what it's worth).

I very much expect developers to check our API docs on regular basis, 
and since we'll be in direct competition with libusb, we might as well 
use commercial practices over content we generate to try to give us some 
edge => a logo + tagline may help people place us on the map.
Now, if you have some better ideas, especially for the tagline, let me know.

The patch also removed DETAILS_AT_TOP that was flagged as obsolete by 
doxygen 1.7.3, as well as the PROJECT_NAME, which may sound counter 
intuitive, but produced duplication with the libusbx from the logo. As 
far as I can see, PROJECT_NAME is only used to display the name in the 
HTML header, and doxygen doesn't care if provided or not.

Since I didn't submit the patches to the mailing list, please try to 
review them and comment if you think they need to be amended.

Regards,

/Pete

[1] 
http://libusbx.git.sourceforge.net/git/gitweb.cgi?p=libusbx/libusbx;a=commitdiff;h=791b7473ec38155ee3d1d9889f3d0f1b4c8f33f0
[2] 
http://libusbx.git.sourceforge.net/git/gitweb.cgi?p=libusbx/libusbx;a=commitdiff;h=ca159f15737e9097a4d031c9950f281c42af040a