[SPARK-8495][SparkR] Add a .lintr file to validate the SparkR files…

… and the `lint-r` script

Thank Shivaram Venkataraman for your support. This is a prototype script
to validate the R files.

R/pkg/.lintr

@@ -0,0 +1,2 @@
+linters: with_defaults(line_length_linter(100))
+exclusions: list("inst/profile/general.R" = 1, "inst/profile/shell.R")

dev/lint-r

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+SCRIPT_DIR="$( cd "$( dirname "$0" )" && pwd )"
+SPARK_ROOT_DIR="$(dirname $SCRIPT_DIR)"
+
+
+if ! type "Rscript" > /dev/null; then
+  echo "ERROR: You should install R"
+  exit
+fi
+
+`which Rscript` --vanilla "$SPARK_ROOT_DIR/dev/lint-r.R" "$SPARK_ROOT_DIR" 

dev/lint-r.R

@@ -0,0 +1,29 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Installs lintr from Github.
+# NOTE: The CRAN's version is too old to adapt to our rules.
+if ("lintr" %in% row.names(installed.packages())  == FALSE) {
+  devtools::install_github("jimhester/lintr")
+}
+library(lintr)
+
+argv <- commandArgs(TRUE)
+SPARK_ROOT_DIR <- as.character(argv[1])
+
+path.to.package <- file.path(SPARK_ROOT_DIR, "R", "pkg")
+lint_package(path.to.package, cache = FALSE)