fixes ensugars signature

If a tree inherited both SymTree and NameTree, that led to problems
ensugars classOf
I thought I've already seen everything in this life

Apparently I haven't :D

It turns out that Typer's context parameter is actually called `context0`,
and Typer.context is a var that, on some occasions, is mutated in-place
during typechecking.

Hence, if you extend Typer and call the constructor parameter `context`,
then you're going to shadow the var from the base class, which will sometimes
lead to super weird errors.
streamlines reflection helpers in scalahost
kills ptpe

Following the idea that ensugaring matters don't belong in Host,
I'm removing the last (huge!) piece of ensugaring - ptpe - which converted
scalac's types to palladium's trees.

At the moment, I'm just removing this functionality altogether and putting up
a stub called Type.syntaxize that in the future will provide analogous logic.
Later on, when implementing Host.attrs, we'll have to implement it.
moves unattributedNodes to Toolkit
Merge pull request #11 from xeno-by/master

finishes the refactoring