Rename protobuf Ruby module to google/protobuf and rework its build
system. The Ruby module build now uses an amalgamated distribution of
upb, and successfully builds a Ruby gem called 'google-protobuf' with
module 'google/protobuf'.
diff --git a/ruby/Rakefile b/ruby/Rakefile
index b782b40..ae7d805 100644
--- a/ruby/Rakefile
+++ b/ruby/Rakefile
@@ -1,35 +1,19 @@
 require "rake/extensiontask"
 require "rake/testtask"
 
-spec = Gem::Specification.new do |s|
-  s.name        = "protobuf"
-  s.version     = "2.6.2"
-  s.licenses    = ["BSD"]
-  s.summary     = "Protocol Buffers"
-  s.description = "Protocol Buffers are Google's data interchange format."
-  s.authors     = ["Protobuf Authors"]
-  s.email       = "protobuf@googlegroups.com"
-
-  s.files       = ["lib/protobuf_c.so", "lib/protobuf.rb"]
-end
+spec = Gem::Specification.load("google-protobuf.gemspec")
 
 Rake::ExtensionTask.new("protobuf_c", spec) do |ext|
-  ext.lib_dir = "lib"
-  ext.config_script = "extconf.rb"
+  ext.ext_dir = "ext/google/protobuf_c"
+  ext.lib_dir = "lib/google"
 end
 
 Rake::TestTask.new(:test => :build) do |t|
   t.test_files = FileList["tests/*.rb"]
 end
 
-task :chmod do
-  File.chmod(0755, "lib/protobuf_c.so")
-end
-
 Gem::PackageTask.new(spec) do |pkg|
 end
-task :package => :chmod
-task :gem => :chmod
 
 task :build => [:clean, :compile]
 task :default => [:build]