fix typo
Add mix testing to nearest_neighbor
Fix mixable_versioned_table to run with linear_mixer
Proted to libc++ for Mavericks.
Fix storage_test for libc++.

storage_test depended on an order of elements in an unordered_map,
so add a sort before assertion.
Fix local_storage_mixture_test.

local_storage_mixture_test compared unordered vectors,
so add sort before assertion.
Fix sparse_matrix_storage_test for libc++.

sparse_matrix_storage_test compared unordered vectors,
so add sort before the comparison.
Fix recommender_base_test for libc++.
Fix lsh_index_storage_test for libc++.

lsh_index_storage::set_and_remove_around_mix was correct unexpectedly on libstdc++ due to its floating point calculation,
so add sort before assertins.
Add initialization in calendar_time's constructor.