disabled jemalloc on osx #859
added real-ish BSON handling for uint64_ts #859

fixes compilation with some compilers, like apple clang
fixed allocation of a shared_ptr #859

apple clang seems to miss the implicit constructor or something
added an include to dictionary.cpp #859

units.h needs it, this just keeps it out of units.h for the time being
fixed v8 compilation on osx #859

added -Wno-tautological-constant-out-of-range-compare and
-Wno-unused-private-field

fixes #859