Conflicts:
	c++/src/capnp/rpc-twoparty.capnp.c++
	c++/src/capnp/rpc-twoparty.capnp.h
	c++/src/capnp/rpc.capnp.c++
	c++/src/capnp/rpc.capnp.h

Grammar fix

Add initial implementation of AnyStruct and AnyList

Fix typos

The 'objectId' field is now deprecated. Long-term, each vat will export no more than one "bootstrap interface" which can be obtained via 'Bootstrap'. Restoring SturdyRefs will be accomplished through higher-level interfaces specific to the VatNetwork in use.

See comments for 'Bootstrap' in rpc.capnp for more discussion.

This removes all instances of the zero-length brand dependencies arrays (04a9c84d).

Ensure CAPNP_LITE is always defined to 0 when not used

Zero-length arrays are a GNU extension.

More CMake Improvements

Also, use pkg-config (if available) to get hints about the paths.

With CAPNP_LITE=1, the command-line tools will not be built, and the
tests cannot be built without EXTERNAL_CAPNP=1 (BUILD_TESTING=0 needs to
be set if the tests are not desired).

Fix occasional evolution-test failure caused by List(Bool)->List(struct) upgrades no longer being allowed.

Fix `CAPNP_LITE` build

The changes to 'capnp/generated-header-support.h' in [b469079d] need to
be applied to both sides of the `#if CAPNP_LITE` conditional.