[qtcontacts-sqlite] Remove partial name matching

Previously we would automatically aggregate contacts under various
conditions where the last name was a match, and there was a partial
match between the first name values.  This has now been removed, as
it produces more false positive matches in some locales than initially
expected.
Merge pull request #169 from matthewvogt/remove-auto-partial-match

[qtcontacts-sqlite] Remove partial name matching