all: Become a Go module (fixes #5148) (#5384)

* go mod init; rm -rf vendor

* tweak proto files and generation

* go mod vendor

* clean up build.go

* protobuf literals in tests

* downgrade gogo/protobuf

vendor/github.com/thejerf/suture/gml

@@ -0,0 +1,47 @@
+#!/bin/bash
+
+# This command wraps up the gometalinter invocation in the pre-commit hook
+# so it can be used by other things.
+
+# If used in a way that the "lintclean" file is in the current working
+# directory, the contents of the lintclean directory will be added to
+# this invocation, allowing you to filter out specific failures.
+
+# Rationale:
+# --exclude="composite literal uses unkeyed field" \
+#  jbowers: I disagree with community on this, and side with the Go
+#    creators. Keyed fields are used when you expect new fields to be
+#    unimportant to you, and you want to keep compiling, i.e., a new
+#    option that, since you weren't using it before, probably want to
+#    keep not using it. By contrast, unkeyed fields are appropriate
+#    when you expect changes to the struct to really matter to you,
+#    i.e., it is discovered that something MUST have a bool field added
+#    or it turns out to be logically gibberish. You can't say that
+#    one or the other must always be used... each has their place.
+#
+# -D gocyclo
+#  jbowers: I consider cyclomatic complexity a bit of a crock.
+
+if [ `which gometalinter` == "" ]; then
+    echo You need to run the \"install_buildtools\" script.
+    exit 1
+fi
+
+EXTRA_ARGS=
+
+if [ -e lintclean ]; then
+    EXTRA_ARGS=$(cat lintclean)
+fi
+
+gometalinter \
+    --exclude="composite literal uses unkeyed field" \
+    -j 4 \
+    -D gocyclo \
+    -D aligncheck \
+    -D gofmt \
+    -D goimports \
+    -D gotype \
+    -D structcheck \
+    -D varcheck \
+    $EXTRA_ARGS \
+    $*