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.

Bka cleanups - fix compiler warnings in kj tests

Implement method kj::StringPtr:parseAs<NUMBER_TYPE>

Warned by gcc 5.3.1 and clang 3.7.0

Warned by gcc 5.3.1

Add Canonicalization