Add mechanism for catching exceptions that has limited use even with -fno-exceptions, as well as a mechanism to detect when a destructor is called during unwind and to avoid throwing in these situations.
Mark every destructor "noexcept(false)" unless it is very clearly noexcept.  The change in C++11 making destructors default-noexcept was a mistake.
Merge pull request #13 from dwrensha/master

update automake include directory to capnp
KJ_EXPECT_{TRUE,FALSE} -> KJ_{,UN}LIKELY
Add Parser combinator framework to KJ (WIP).
Add file that should have been added earlier.
Refactor Tuple and split it and Vector out into their own headers.
Refactor parser code more.
Enable some useful Clang warnings, fix some bugs it detected.  Especially, eliminate all dynamic initializers.
Fix endian tests when compiling a single test binary.  There was an ODR violation.
Unset LD_PRELOAD while generating exception stack traces via addr2line.
Make tests pass with -fno-rtti and -fno-exceptions.
Fix some GCC warnings.
Merge branch 'master' of https://github.com/kentonv/capnproto
Apply some capnproto -> capnp renames that didn't happen before, update docs, put samples in a place where they are easy to compile.
Update blob docs.