Osm xml importer

This PR adds a new import to H2-spatial-Ext module to import an OSM XML file to a database.
A specified datamodel is build for each osm file. It contains 10 tables that reproduce as much as possible the OSM conceptual schema. 

Syntaxe : 

```mysql
CALL OSMREAD('/tmp/viveLesBretons.osm','BRETONS');

```

Where the first argument correspond to the path of the file and the second argument is used to set a prefix to each table. e.g : BRETONS_NODE, BRETONS_WAY...