Try to give better scores to the different tokens of a name (Closes #1276)

Try to give better scores to the different tokens of a name (Closes #1276)

This also remove the initial lastname/firstname from the source of tokens
in order to avoid searches that return result without the searched
token.

Index particle with score = 0.

Signed-off-by: Florent Bruneau <florent.bruneau@polytechnique.org>