chore(utils): move to dgeni-packages

These util files are not really for dgeni, they are to support document
processors that are actually in dgeni-packages.

BREAKING CHANGE:

The util modules have now moved to dgeni-packages, since they were quite
specific to the document processors there.  If you relied upon any of
these in your own custom packages then you should look in dgeni-packages
to find out where they have gone.
refact(doc-processor): move pseudo processors to dgeni-packages

Dgeni should not know about this pseudo packages since in a different
setup they may not makes sense - for example "tags-extracted" assumes
that you have tags in your doc source files.

BREAKING CHANGE:
Dgeni no longer defines any pseudo packages - they have been moved to
the relevant packages in dgeni-packages.
If your own packages referenced these pseudo processors then you will
either need to use the packages in dgeni-packages (v0.9+), which now
define them or provide them yourself explicitly in you config.
get access to these pseudo
chore(spec/beforeEach): make logging silent

Spying on the logger was not actually working.  This change just makes
the console logger silent but actually we should add our own custom
transport that saves to memory so we can check what is being logged
as part of the tests.
docs(guide/what is dgeni): add and extend the doc