Fixes for windows

Fix that Thread::detach() prematurely deleted objects the thread might be using.

Fixed typos

include stdlib.h to fix build on OSX

Only Glibc on Linux has execinfo.h

Fix as done elsewhere so that it builds correctly on Musl libc
as well as Glibc.
Signed-off-by: Justin Cormack <justin@specialbusservice.com>

capnp/Request: warn on unused result for send()

Mark Builder::operator Reader/asReader() member functions const.

Add missing include when building on Linux

Add missing include when building on Linux

Discovered trying to build on Android using CMake.  UIO_MAXIOV is only
exported by the linux/uio.h header which was never included.  Not sure
how normal Linux builds work.

Add missing reinterpret cast from const void* to const byte*.

Remove -pthread compile flag when building under Android.  ANDROID cmake
variable exported by android-cmake project.

Fixes #349.

prevent use-after-free in internal compiler API

capnp-c++: implement asGeneric method for outer template contexts

Since simply fixing the bug would silently break backwards-compatibility for affected schemas, we instead throw an exception to alert developers.

See Issue #344 for more details.

https://github.com/sandstorm-io/capnproto/issues/334

fix spelling of "inundating"

capnpc-c++: fix generated code for union inside template

This is blunt: A peer can choose to stop reading new messages from a connection whenever the calls in-flight cross a certain threshold. This is needed in Sandstorm to prevent errant (or malicious) apps from consuming excessive RAM in other parts of the system by flooding them with calls.

KJ_DEFER fix doc: deferred code is run at scope exit

kj/io: Make FdOutputStream::write fallback to OutputStream::write.