gEDA: Big changes to RC file system

[sdb-at-NOSPAMcloud9_dot_net (Stuart Brorson)]

Hi Guys --

Several newbie users have said that the symbol files were
misconfigured when they tried using gschem.  In particular, they said
that locally defined symbol files didn't always work correctly.  These
are symbol files pointed to by the local gafrc living in your
working directory.

This is nonsense because the symbol files always install correctly.
Instead, I believe what is  happening is that newbies sit in directory
A, and try to open a schematic in directory B.  In the currently
released version  of gEDA/gschem, this fails because gschem only looks
at the gafrc in directory A.  It doesn't read the gafrc in direcotry B
so it can't find the sym files local to the schematic in directory B.   

I have fixed this by making a number of changes to libgeda.  
In particular, gEDA/gaf now tries to open the gafrc living in the same
directory as your schematic.  Everytime you open a schematic, it
checks if it needs to open the gafrc, and if so it opens it.

These changes meant that I needed to also change gschem, gnetlist,
gattrib, etc.  Specifically, I now call all the g_rc_parse stuff with
w_current as the first arg.  w_current now holds a GList of all RC
files which have been visited, and if a new file is opened, the
corresponding RC file is also opened if it isn't already open. 

I also refactored code in all the programs which rely upon these
functions in libgeda.

Question for Ales:  I have tested this stuff on my box and it seems to
work.  I would like to have others test it too.  I can just upload it
to CVS, but it represents a lot of changes.  Although I have tested
it, there is always the chance that it breaks something.   So, hould I
just close my eyes and upload it, or would you like to look at it
first?  Or perhaps put it in an experimental branch of the code?  

Finally, are there any volunteers who want to take the code out for a
long test drive? 

Stuart