Make gnu++11 the default standard version.

There are a _lot_ of users of `typeof` in the tree, and they'll need a
GNU flavored standard. Rather than fixing up all of these
individually, let's just use gnu++11 as the default.

Bug: 18466763
Change-Id: Ia1bd3adaa74fadba259fda3d37653fb8d5cff69a
Kill unused HAVE_WRITEV.

Change-Id: I6e4df2449b27d67f207fc53b19e49b21f9cee611
Merge "Kill unused HAVE_WRITEV."
Merge "Make gnu++11 the default standard version."