Remove code duplication and fall back to trying directly if the proxy
isn't available. With this, tests still work if netd is dead (perhaps
because you've run "adb shell stop", or because you're running on the host).
Bug: 18547878
Change-Id: Ia4a9aa18b1fc79e09735107246989fa7fc6c8455
Replace iface cache key with netid.
Replace _mark with netid.
Mark sockets used to test IPv4/IPv6 support as well as sockets
used to determine source address for rfc6724 sort.
Remove pid/uid mappings (functionality moved to system/netd).
Do not create resolv_cache when it does not exist, but rather only
when DNS configuration is supplied.
Clean up unused functions.
Change-Id: I9ccfda2902cc0943e87c9bc346ad9a2578accdab
This is part of the upstream sync (Net/Open/Free BSDs expose the
nameser.h in their public headers).
Change-Id: Ib063d4e50586748cc70201a8296cd90d2e48bbcf
