While comments should appear after the code, some examples violate the convention. This commit enforces the rule.

* Announce 0.6 release on blog, and update site.

* When pushing capnproto-next site, include future blog posts.

* Deeper headings.

* Linkify people's names to Github profiles, and finish sentence about JSON.

* Link to exact second in JGC video.

Fixes #196

This change takes a comment about lazy execution from
https://github.com/sandstorm-io/capnproto/issues/263#issuecomment-158564701 and
adds it to the C++ RPC documentation.

Although lazy execution is described in `Promise::then()` method documentation,
it's unfortunately buried in the *Advanced implementation tips* section, and
described as an optimization rather than as a more general feature of the
asynchronous execution model. Since I recently got tripped up by this behavior,
I thought it would be worth trying to document better.

Server::Context does not have method getRequest

setup-autotools.sh is no longer needed as of 6cd25260.

The instructions work without having Subversion installed as well.

Update comparison blog post to note that proto3 removes unknown field retention, for some ridiculous reason.