Updates the name of translation module
Marks next release as 0.2.0, since now translation is almost done.
Makes the translation.cmp total by placing some disambiguation rules.
Makes cloning of terms a bit more general
Makes translation.cmp a total ordering comparison function
Removes superfluous comment
Allows cotraverse_expression to be passed a query object.

This was a bug cause the documentation stated that you may pass a query object.
Small change in the way operators are tested.
Requires xoutil 1.2.4 to allow the using of stacked context's data.
Fixes tests so they reveal a big issue.
Removes QueryPart. This implies a big commit with several changes in design.

The removal was provoked because QueryParts won't actually help in the case of
the subquery like::

    these(parent
          for parent in this('parent')
          if any_(child for child in parent.children if child.age < 6))

In this case the previous mechanism of letting the first argument (a QueryPart
usually) to be who emits the built expression fails, because the argument to
``any_`` was a generator object.

So expressions would have to emit themselves if any bubble was around. That
fact removed the need of a QueryPart.

But several edge cases arouse:

- Cross-bubbling of `parent.children` (part, token) duality. Since the part is
  emitted to the upper bubble, when the token is emitted it does not realizes
  it sibling part was emitted and cannot squash it.
Updates the change history
Fixes some minor bugs
Fixes looking for values in the Python's VM
Recodes the translation for logical operations.
Documents the state of translator
Documents the Py translation module.
Marks next release as 0.2.1
Updates the name of the common translation package
Corrects grammar in README