Introduce method syntax for function definitions

foo!bar x:
	pass

is now short for:

labda x:
	pass
set-to foo :bar
Make imported namespaces global in the REPL

Since every entered chunk is its own file, importing modules in
the interactive interpreter was a bit iffy, since the namespace
was made local (which is great otherwise).

Note that recursive importing is now broken when using the REPL.

Example:

<1:1> !import!foo

(in foo.deja:)
!import!bar

<2:1> . bar
{ ... }
<3:1> #oops, should not be able to see that...
Make Scope 8 bytes smaller
Change the way dictionary defaults are done

Now, default values are a feature of dicts, not of HashMaps. That
means HashMaps belonging to Scopes don't have the asdefault member
any more. And that means Scopes are another 8 bytes smaller.
Make once use pass instead of creating a labda