I'm pretty happy about how lightweight the implementation turns
out to be.

The ":" now takes care of scanning for ";". Conceptually, having
";" as an immediate word is slightly simpler than the approach in
this commit, but when bootstrapping is involved, this simpler
approach gets murkier.

Moreover, it got even murkier-er when trying to de-stabilize EXIT,
so here we are.

This was becoming heavy to manage.

This is the first commit I do entirely in VE. It's a habit I'm planning
on taking as it helps a lot to find usability issues.

and renamed it "Core words". Also, reworded the presentation.

Finally got rid of the XPACKed core and managed to cross-compile
all core words, which greatly simplifies the bootstrapping process.

TODO: implement X['] so that I can remove those XCURRENT patterns.

This leaves space for xcomp-core which is growing.

This allows us to move words like ABORT" to xcomp-core, which is
I think the last roadblock before being able to unify all drivers
into a single xcomp layer.

And refreshed description.

With all this recent movements, we had a bit of a fragmentation
issue.