add <cstdarg> and update <type_traits>

[ZERICO2005]

Changes:

• Fixed white-space and line-endings in libcxx headers. This should makes the diffs easier to follow when we switch to EASTL or another C++ STL.
• Made small additions to <type_traits>
• Added <cstdarg>
• Fixed <stddef.h>/<cstddef> in C89/C++98. As explained here utility and type_traits don't work in C++11 #534 (comment), at a bare minimum we should maintain support for stddef/stdarg for all versions of standard C/C++.