Improvements to charge/contracts admin (allow to filter by contract category)

Signed-off-by: Raphael Lullis <raphael@lullis.net>
Improvements to charge/contracts admin (allow to filter by contract category)

Signed-off-by: Raphael Lullis <raphael@lullis.net>
UserCostView should show the cost per user.

Signed-off-by: Raphael Lullis <raphael@lullis.net>