Consider 2.0 as next release number

[mboeringa]

Since there are some big changes for osm2pgsql upcoming, including a new 'middle' database format / schema, new options for expiry, faster -append etc, wouldn't it be a good idea to have 2.0 as release number instead of 1.9.0?

Or is 2.0 going to be where the old 'pgsql' output is going to be dropped (if there are any plans for that), and possibly the experimental generalization options integrated?