This change fixes a parallel make which always failed with "cannot find
-lprotobuf".

For C++ static libraries, protobuf was already added as dependency, see
commit 5383062d.

- Added ptag ignore annotation threshold
- prefixed everythig with grpc_
- removed spurious annotations in channel_create.c and client_channel.c
- removed stap_probes.h (it's generated from stap_probes.d by make)
- Updated Makefile and its template with the right way to generate stap
  probe headers from its .d definition.

This commit includes a faulty Makefile to be fixed in a follow commit.

A bunch of autogenerated variables are currently useless, because of tests actually having no source code attached to them. Let's avoid emitting useless code in that case.

dependencies.

variables to set up the GRPC_LATENCY_PROFILER preprocessor macro so that timing
actually takes place.

protobuf plugins. This requires WORKSPACE to define these external
dependencies for openssl and protobuf, for examples:

bind(
  name = "libssl",
  actual = "//third_party/boringssl:boringssl",
)

# Library needed to build protobuf codegen plugin.
bind(
  name = "protobuf_compiler",
  actual = "//third_party/protobuf:protoc_lib",
)

# Library that C++ code generated by protobuf C compiler should depend
# on.
bind(
  name = "protobuf_clib",
  actual = "//third_party/protobuf:proto_lib",
)

This resolves a blocker stopping a clean linuxbrew install to work with one of
the wrapped libraries.

Enables the installation of dylibs to the MacOS prefix, and ensures that the
install name of the dylibs are just their file names rather than their relative
paths from project root when built.