Release 1.7.1

This release fixes a few small bugs in osm2pgsql and closes some gaps in the geometry processing code released in 1.7.0. It also contains some security-related fixes as a result of the security audit.

• Added as_multipoint() function to complement as_multilinestring() and as_multipolygon().
• The functions as_multipoint(), as_multilinestring(), and as_multipolygon() will now always return single geometries if possible. Single geometries are always allowed where multi geometries are allowed, so this does't break anything.
• The centroid() function now works for all geometry types.
• New length() function to compute the length of a geometry in map units.
• New reverse() function to turn geometries around (can be useful for ways tagged with oneway=-1).
• The simplify() function is now available for multilinestrings, too. (Not for polygons yet.)
• All example code in the flex-config directory has been updated for the new geometry handling capabilities.
• Create nicer error messages when trying to access a missing database extension, schema, or tablespace.
• Better checking of names (of tables, schemas, etc.) used in SQL in osm2pgsql and osm2pgsql-replication to avoid potentional SQL injection issues.
• Fix: Make sure relation members show up in the correct order in multi-geometries when using slim mode.
• Fix: Do not try to run ST_IsValid() on create_only columns.
• osm2pgsql-replication: The database parameter may be empty when connection parameters are supplied via environment variables.
• osm2pgsql-replication: when installed, now runs the osm2pgsql binary that was installed with it to avoid potential security issues through PATH manipulation.
• osm2pgsql-replication: Meaningful error when middle tables do not exist or the prefix is a bad one.