Merge pull request #106 from jjwchoy/master

Fixed compile --src-prefix help text
Added hex binary literals
Allowing whitespace in between octets
oops, whitespace was not being discarded. fixed
Added test for binary hex literal
Changed hex integer literal parsing rule
Added binary hex literal examples to docs
Merge pull request #107 from jjwchoy/hex-binary-literal

Added hex binary literals
Fix template method that doesn't actually compile when used.
Merge branch 'master' of github.com:kentonv/capnproto
Update blog post to reflect that FlatBuffers now supports optional bounds checking.
Add configured includedir as a default import path

Protected by an ifdef to avoid tripping up non-autotools builds
Support for exception backtraces on OS X.
Merge pull request #109 from greedy/add-includedir-to-imports

Add configured includedir as a default import path
Consolidate Linux and OS X versions of getStackSymbols().
Replace 'goto' error handling with KJ_DEFER.
Merge pull request #111 from partylemon/ExceptionBacktraces

Support for printing exception backtrace symbols on OS X.
Fix typo. Fixes #112.
Merge branch 'master' of github.com:kentonv/capnproto
Fix two subtle bugs with embargos, and improve docs.

Bug 1
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If a Resolve message indicated that the promise had been rejected, the code would see the error cap as a local cap and erroneously believe that the promise had resolved back to a local capability, thereby requiring a Disembargo to be sent. The peer, on receiving the nonsensical Disembargo, would throw an exception and close the connection.

The error message seen was: "expected target->getBrand() == this; 'Disembargo' of type 'senderLoopback' sent to an object that does not point back to the sender."

Bug 2
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Disembargos are sent not only in response to Resolves, but also Returns, since capabilities in a returned message were previously accessible as PromisedAnswers. This means that we must apply the same rule that states that once a promise has been resolved, the promise must from then on forward all messages it receives strictly to the object to which it resolved, even if that object is itself a promise which later resolves to somewhere else. The code which sends Resolve messages was doing this correctly, but the code sending Return messages was not. They now both operate correctly. I've also added more explanation to the documentation in rpc.capnp.

The error message seen was: "expected redirect == nullptr; 'Disembargo' of type 'senderLoopback' sent to an object that does not appear to have been the object of a previous 'Resolve' message."