Remove -std=foo compiler flags
These flags are only really useful for linting. They put GCC and other
compilers into `__STRICT_ANSI__` mode. That can make systems stuff
slower, in favor of standards conformance, since it may cause headers to
remove platform specific goodness. It also makes builds more painful on
old distros that have the functions we need, but track an older version
of the standards where those functions weren't strictly available. One
such example is mkstemp(). It's available everywhere in practice, but GA
Ubuntu in strict ansi mode complains about it. If we don't use mkstemp()
then that'll put us on the security radar with other platforms.
