opaque closure

This reverts commit d499e739.

stdout is where all the useful info is, not stderr.

Issue #1359

Returns the home directory of the user as appropriate for the platform.

Issue #1359

Now, if you have a tag named "foo", a variable declaration like
"let foo..." is illegal. This change makes it possible to eliminate
the '.' after a nullary tag pattern in an alt (but I'll be doing
that in a future commit) -- as now it's always obvious whether a
name refers to a tag or a new declared variable.

resolve implements this change -- all the other changes are just to
get rid of existing code that declares variables that shadow tag
names.

map::get is evil -- just say no!

adding some misc functions and some functions just for [u8]

Interns non-static dicts to heap-allocated equivalents so that they no
longer have stack scope.

Closes #1436

Issue #1437

We have a bunch of these in the repository.

Issue #1436

It would occasionally pass the wrong type parameter, when calling
a generic method from a generic impl on a bounded param type.

save SSE regs in i386 (we ought to, though!)