Update mongodb formula

 * On 10.9, use libc++ (not libstdc++) for devel and HEAD builds
   (See also upstream https://jira.mongodb.org/browse/SERVER-12682)
 * Pass --full flag to install headers and library also.
 * Add option --with-boost, to pass --use-system-boost to scons (avoid linking issues with the created library).
mongodb: update 2.4.9 bottle.