Bump to 0.2.17

Add SO_REUSEPORT to mips64

Go back to stable for rustdoc

Fix the build on s390x

pass --target on appveyor

Make the AF_NETLINK constant available for Android

Currently the `AF_NETLINK` constant is not available for Android, but [it has the same value as on Linux](https://android.googlesource.com/kernel/common/+/android-4.4.y/include/linux/socket.h#177). To fix it, this patch moves the definition to the common `notbsd/mod.rs`.

(this fixes an [issue we found in Servo](https://github.com/servo/servo/issues/13154#issuecomment-251325701))

Use workspaces in this repo

Also cache on appveyor to speed up builds.

Also cache on appveyor to speed up builds.

Haiku: Add missing EAI_SYSTEM const

define more MSG_NOSIGNAL

follow-up on rust-lang/rust#36824

Typo in unix/solaris/mod.rs

Define CLONE_NEWCGROUP

Should be fairly self explanatory.

* Override the compiler via CC; ./configure can't seem to detect it.
* Unset CROSS_COMPILE when running make. Per the comment, we otherwise
  end up invoking commands like i686-ar.

Musl 1.1.14 defined these incorrectly, and we followed suit. They're
fixed in 1.1.15, so we fix them here as well.

Since these are kernel ABIs, the correct values match other libc
implementations, so we move them up to the topmost module possible.

Specifically:

* Update the base docker images to ubuntu 16.10
* Update musl to version 1.1.15

This is necessary since the versions we were previously using do not
define CLONE_NEWCGROUP, so adding the symbol to the libc crate causes
test failures.

Currently restricted to non-Android Linux. In theory this should work on
Android as well (since it's a function of the kernel ABI), but the
released version of the NDK doesn't export it, so putting it in
`notbsd/mod.rs` makes Travis very unhappy.

Added all additional ptrace options.

Added additional PTrace Flags.

All the `PTRACE_O` are flags options values that are passed with `PTRACE_OPTION`.

The `PTRACE_PEEKSIGINFO_SHARED` is used for setting/fetching signal masks when interacting with thread groups not individual threads.

`SYSEMU` stuff I pulled from the kernel sources. As far as I can tell these flags haven't been added to `<sys/ptrace.h>`, which is weird because the two `SYSEMU` calls have been live on x64 since 2011. I'm starting a thread on kernel-newies about it.

Haiku: More build fixes

Haiku: Add in missing build-time types, fix module usage

Working through the few final remaining build issues for the Haiku target.

Add `pthread_mutex_timedlock`

Add support for Haiku x86 and x86_64

* Rework of original patches from Niels Sascha Reedijk
  that include style and build fixes for libc master

Use correct type for c_ulong and c_long on 32-bit netbsdlike