If we are building protobuf because of an incompatible out of tree protobuf installation, then make sure that we don't accidentally use that versions includes.

Also, fixing protobuf in-place compilation for real, this time.

Let's not install our potentially broken version of protobuf onto the system and pollute people's environment.

-) Secure files shouldn't be in the base grpc.
-) grpc++ depends on gpr.
-) grpc++ depends on protobuf (!)

was used.

-) renamed cpp_plugin and ruby_plugin to grpc_cpp_plugin and grpc_ruby_plugin.
-) installing plugins.
-) install will now run protobuf's installation too.
-) adding documentation about installation prefix.

Not yet fully building due to some gtest anomalies on Mac.

Auto-dependency building doesn't do this (yet)

Re-enabling errors on warning, disabling unused parameter warning, and fixing all subsequent errors.

We have too many warnings going unchecked. The next step is to
fix all these warnings. One can re-enable errors on warning by
doing: CPPFLAGS=-Werror make in order to start fixing them.

Hopefully works around #90.

Instead of C++ or not C++, name C++ and C, in preparation for being able to name other languages in the future.

The source code of the libraries depends on openssl being built, as it will setup the headers.
Since we don't know exactly which source depends on openssl (we could start flagging it in build.json, but that'd be painful), we just flag all the source for every ssl-enabled library to depend on openssl being built.

Allows us to collect profiles of the open source build using gprof.

Files that have dependencies on phony targets are always remade, leading
to much unnecessary compiling of the C++ tests.

They're trivially recreatable from the _OBJS variables now.

If we don't have a .o, we don't need dependencies, so skip the setup
step of building them. Instead, when building the .o, we generate the
.dep and output it (to objs/ to make the rules a little easier). The
next run of make will include the dep file and any dependencies will be
picked up.

This change also disables the disabling of dependency checking if we
have zlib or openssl being compiled from third_party. Additionally it
inverts the logic for including dependencies from ONLY if we are doing a
clean to ONLY if we are NOT doing a clean.

It's safe enough to just delete the build product directories.