Add optimized indexing capabilities for phone number values.

Add optimized indexing capabilities for phone number values.

Creating indexes with normalized phone numbers permits fast phone number
lookup even if the stored vCards or the queried phone numbers are freely
formatted or incomplete.

The numbers are formatted according to E.164 when building the index.
Incomplete numbers are prefixed with a country-code matching the current
locale settings while processing query results.

Updated Mathias Hasselmann's patch on bug 689622 to apply to current master.