[gta02-core] Switching to the Library of Everything

[Werner Almesberger]

Rene remarked that the use of the per-component libraries is creating
an increasing number of unnecessary commit conflicts, and that we might
as well start using the combined library.

The main reason for having per-component libraries is to make it
easier to track down changes. If we continue making changes only to
the per-component libraries and merge them into the combined library
by script, this doesn't change.

Another use using the per-component libraries for the "main" schematics
was to have a profile (gta02-core.pro) that contains all the libraries,
so that they can be edited quickly. We'd lose this feature if using
only the combined library.

I've now added a new set of schematics and profile in components/,
with the full list of component libraries and the schematics consisting
of nothing but a big warning.

When editing components, please use this one from now on, e.g., like
this:

cd components
eeschema `pwd`/gta02-core-comp.sch

I've checked in the now pleasantly simple gta02-core.pro in
trunk/gta02-core/ in a separate commit (revision 5153), in case there
are unintended consequences.

- Werner