installation: 1.X to 2.0 upgrade recipes

Here is an attempt to fill inn the gaps of the upgrades from v.1.x to v.2.0.

Running alembic after applying these on a master installation, gave the following output:
https://gist.github.com/jalavik/66d909e00d12ee2be3fe

Most of it are not applicable, except maybe the column change in the `tag` table, but I am not sure if this one is necessary..

Touches #1613
What we thought of doing was, for every major.minor release, a new point in upgrade space like `invenio_release_1_2_0.py` would be released, where all previous ugrader arrows would join again.  In this way we would have nicely represented point releases.  (We've not been doing that for past ones, though.)