People see files named "md5" and get worried about security issues, even though we're using it only as a *non-cryptographic* PRNG. So, I renamed the files to type-id.*, encapsulated the code better to make clear that it's only used to generate type IDs, and added comments clarifying that we're not expecting it to be collision-proof.

Fixes #482.

We'll need to update the configure script to check for OpenSSL and conditionally build this. Ekam users will need to add -DKJ_HAS_OPENSSL to their CXXFLAGS if they've arranged to link against the correct libs.

Remove references to obsolete isCallersFault

Misspelt macro name in undef

It looks like it's pretty normal for browsers to do this.

The entity-body would never be marked "done", breaking the pipeline for subsequent requests/responses.

(In practice `Content-Length: 0` is rare since normally only GET requests don't have content and they don't pass `Content-Length` at all.)

At some point isCallersFault was marked as obsolete, but the description
of abort still referenced it, suggesting particular usage. This patch
removes said references.

Since `git-diff` does *such* a good job with prose: This just removes
the two parentheticals and re-flows the paragraph.

or, the world's least significant pull request.

kj::Directory::list*() should return sorted lists to avoid non-determinism.

fix typos: complied -> compiled

* 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.