Add xAL v3.0 address examples

[DiegoVinasco]

3 examples are added to the building folder:

• a free text address
• a fully structured address
• an address with common type attributes

Also, add a link to the latest xAL 3.0 examples from the OASIS website.

Finally, apply a small fix to the relative paths of xsi:schemaLocation attributes in example files so that they properly point towards the local schema.