Moved ByteBuffer/BitBuffer into rtc_base_approved.

Also pulls in constructormagic.h, byteorder.h, and basictypes.h.

BUG=
R=pthatcher@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/49069004

Cr-Commit-Position: refs/heads/master@{#9062}
2 files changed