Remove Gradle plugin dependency on Apache Commons

We have used `commons-lang` to detect
if current OS is a Windows.
`org.apache.commons.lang.SystemUtils` also
tries to parse JDK version in `clinit` and,
as of AC version 2.4, fails on JDK 9.

I preferred to remove the dependency completely
and copy an implementation of `isWindows` from Intellij
platform, because the code is quite simple
and minimizing unnecessary dependencies will help to avoid
compatibility problems in future.

Gradle plugin also declares a dependency on `commons-io`,
but it seems unused, so the dependency is also removed.

    #KT-18832 fixed

libraries/tools/kotlin-gradle-plugin/build.gradle

@@ -35,9 +35,6 @@ dependencies {
     compile "org.jetbrains.kotlin:kotlin-compiler-runner:$kotlin_version"
     compile "org.jetbrains.kotlin:kotlin-annotation-processing:$kotlin_version"
 
-    compile 'commons-io:commons-io:2.4'
-    compile 'commons-lang:commons-lang:2.4'
-
     compileOnly 'com.android.tools.build:gradle:2.0.0'
     compileOnly 'org.codehaus.groovy:groovy-all:2.3.9'
     compileOnly 'org.jetbrains.kotlin:gradle-api:2.2'

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinGradleBuildServices.kt

@@ -16,7 +16,6 @@
 
 package org.jetbrains.kotlin.gradle.plugin
 
-import org.apache.commons.lang.SystemUtils
 import org.gradle.BuildAdapter
 import org.gradle.BuildResult
 import org.gradle.api.invocation.Gradle
@@ -27,6 +26,7 @@ import org.jetbrains.kotlin.com.intellij.openapi.vfs.impl.jar.CoreJarFileSystem
 import org.jetbrains.kotlin.compilerRunner.DELETED_SESSION_FILE_PREFIX
 import org.jetbrains.kotlin.compilerRunner.GradleCompilerRunner
 import org.jetbrains.kotlin.gradle.tasks.AbstractKotlinCompile
+import org.jetbrains.kotlin.gradle.utils.isWindows
 import org.jetbrains.kotlin.incremental.BuildCacheStorage
 import org.jetbrains.kotlin.incremental.multiproject.ArtifactDifferenceRegistryProvider
 import org.jetbrains.kotlin.incremental.relativeToRoot
@@ -190,7 +190,7 @@ internal class CompilerServicesCleanup() {
         // clearing jar cache to avoid problems like KT-9440 (unable to clean/rebuild a project due to locked jar file)
         // problem is known to happen only on windows - the reason (seems) related to http://bugs.java.com/view_bug.do?bug_id=6357433
         // clean cache only when running on windows
-        if (SystemUtils.IS_OS_WINDOWS) {
+        if (isWindows) {
             cleanJarCache()
         }
 

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/utils/systemUtils.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed 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.
+ */
+
+package org.jetbrains.kotlin.gradle.utils
+
+import java.util.*
+
+// Based on org.jetbrains.kotlin.com.intellij.openapi.util.SystemInfoRt from Intellij platform
+internal val isWindows: Boolean =
+        System.getProperty("os.name")?.toLowerCase(Locale.US)?.startsWith("windows") ?: false