OX 10.9 Mavericks Fix

Mavericks doesn't like these, because it already includes strlcat and strlcpy somewhere.

This uses the same fix used for [JRuby](https://github.com/jruby/jruby-launcher/pull/6)

Should fix Issue [27](https://code.google.com/p/py-setproctitle/issues/detail?id=27)

Turns out clang has a bunch of builtins 

From this [post](https://code.google.com/p/go/issues/detail?id=6506#c21)

The problem is that clang has a bunch of "builtin" function definitions, and those builtin ones serialize into dwarf using ulong instead of size_t. It only happens for these builtins, not for all functions. So we can special-case the builtins in cmd/cgo. 

The full set, from clang/Basic/Builtins.def, is 

LIBBUILTIN(calloc, "v*zz",        "f",     "stdlib.h", ALL_LANGUAGES)
LIBBUILTIN(malloc, "v*z",         "f",     "stdlib.h", ALL_LANGUAGES)
LIBBUILTIN(realloc, "v*v*z",      "f",     "stdlib.h", ALL_LANGUAGES)
LIBBUILTIN(memcpy, "v*v*vC*z",    "f",     "string.h", ALL_LANGUAGES)
LIBBUILTIN(memcmp, "ivC*vC*z",    "f",     "string.h", ALL_LANGUAGES)
LIBBUILTIN(memmove, "v*v*vC*z",   "f",     "string.h", ALL_LANGUAGES)
LIBBUILTIN(strncpy, "c*c*cC*z",   "f",     "string.h", ALL_LANGUAGES)
LIBBUILTIN(strncmp, "icC*cC*z",   "f",     "string.h", ALL_LANGUAGES)
LIBBUILTIN(strncat, "c*c*cC*z",   "f",     "string.h", ALL_LANGUAGES)
LIBBUILTIN(strxfrm, "zc*cC*z",    "f",     "string.h", ALL_LANGUAGES)
LIBBUILTIN(memchr, "v*vC*iz",     "f",     "string.h", ALL_LANGUAGES)
LIBBUILTIN(strcspn, "zcC*cC*",    "f",     "string.h", ALL_LANGUAGES)
LIBBUILTIN(strspn, "zcC*cC*",     "f",     "string.h", ALL_LANGUAGES)
LIBBUILTIN(memset, "v*v*iz",      "f",     "string.h", ALL_LANGUAGES)
LIBBUILTIN(strlen, "zcC*",        "f",     "string.h", ALL_LANGUAGES)
LIBBUILTIN(snprintf, "ic*zcC*.",  "fp:2:", "stdio.h", ALL_LANGUAGES)
LIBBUILTIN(vsnprintf, "ic*zcC*a", "fP:2:", "stdio.h", ALL_LANGUAGES)
LIBBUILTIN(alloca, "v*z",         "f",     "stdlib.h", ALL_GNU_LANGUAGES)
LIBBUILTIN(stpncpy, "c*c*cC*z",   "f",     "string.h", ALL_GNU_LANGUAGES)
LIBBUILTIN(strndup, "c*cC*z",     "f",     "string.h", ALL_GNU_LANGUAGES)
LIBBUILTIN(bzero, "vv*z",         "f",     "strings.h", ALL_GNU_LANGUAGES)
LIBBUILTIN(strncasecmp, "icC*cC*z", "f",   "strings.h", ALL_GNU_LANGUAGES)
LIBBUILTIN(strlcpy, "zc*cC*z",    "f",     "string.h", ALL_GNU_LANGUAGES)
LIBBUILTIN(strlcat, "zc*cC*z",    "f",     "string.h", ALL_GNU_LANGUAGES)