Bug 923886 - Remove the Assertions.h #include from Char16.h; r=Waldo
Bug 924012 - Provide a HashString version for char16_t if needed; r=Waldo
Bug 924014 - Do not rely on std::numeric_limits<char16_t> being available; r=Waldo
Bug 924011 - Do not assume that PRUnichar and UChar are the same type; r=Waldo