Failed to notice this because only the cmake build refers to it, and this only makes cmake fail on installation, which was never quite tested.

Tweak installation documentation

I've added -Wextra as well as removed some of the -Wno-* flags and fixed issues in the code.

Also fixed the cmake build to put user-defined flags after default flags so that they can be overridden.

Minor fixes to comments in rpc.capnp

The idea behind the directory organization was that we might have official implementations for other languages in other top-level directories, as siblings to the c++ directory. It seems implausible that we'd use CMake as a meta-build-system over all of these.

Another reason for this change is that the release tarball actually contains only the c++ subdirectory. We probably want to include cmake files in the release.

Remove a reference to Main, add a comment about the legality of acceptFromThirdParty, and fix a few typos and one pervasive grammatical error.

Add an easier way to read a message directly into a builder. Requires a copy for security/validation.

This is not currently used, but eventually we'll use this to support efficient inter-thread messaging.

That said, I've decided that inter-thread messaging is complicated and I don't want to work on it right now.

CMake support for MSVC/Visual Studio

fix some typos