Add a Go language example.

This follows the other examples so that it can be used as a tutorial,
such as the ones at:
  https://developers.google.com/protocol-buffers/docs/tutorials

Even though Go generally does not use Makefiles, I added targets for the
Go examples to be consistent with the other languages.

Edit:

Fix Travis run. Change to use $HOME instead of ~. Add protoc to path.
GOPATH entry cannot start with shell metacharacter '~': "~/gocode"

Edit(2):

Fix Go code style to address comments.

1 files changed, 25 insertions, 0 deletions

diff --git a/examples/README.txt b/examples/README.txt
index f5530a5e..e6f30370 100644
--- a/examples/README.txt
+++ b/examples/README.txt
@@ -27,3 +27,28 @@ These examples are part of the Protocol Buffers tutorial, located at:
 * Note that on some platforms you may have to edit the Makefile and remove
 "-lpthread" from the linker commands (perhaps replacing it with something else).
 We didn't do this automatically because we wanted to keep the example simple.
+
+## Go ##
+
+The Go example requires a plugin to the protocol buffer compiler, so it is not
+build with all the other examples.  See:
+  https://github.com/golang/protobuf
+for more information about Go protocol buffer support.
+
+First, install the the Protocol Buffers compiler (protoc).
+Then, install the Go Protocol Buffers plugin
+($GOPATH/bin must be in your $PATH for protoc to find it):
+  go get github.com/golang/protobuf/protoc-gen-go
+
+Build the Go samples in this directory with "make go".  This creates the
+following executable files in the current directory:
+  add_person_go      list_people_go
+To run the example:
+  ./add_person_go addressbook.data
+to add a person to the protocol buffer encoded file addressbook.data.  The file
+is created if it does not exist.  To view the data, run:
+  ./list_people_go addressbook.data
+
+Observe that the C++, Python, and Java examples in this directory run in a
+similar way and can view/modify files created by the Go example and vice
+versa.