Build: add maven.repository.mirror property

May be used to add additional repository to all projects

(cherry picked from commit d8407b9)

build.gradle.kts

@@ -14,7 +14,10 @@ buildscript {
 
     kotlinBootstrapFrom(BootstrapOption.TeamCity("1.2.40-dev-967", onlySuccessBootstrap = false))
 
+    val mirrorRepo: String? = findProperty("maven.repository.mirror")?.toString()
+
     val repos = listOfNotNull(
+            mirrorRepo,
             bootstrapKotlinRepo,
             "https://jcenter.bintray.com/",
             "https://plugins.gradle.org/m2",
@@ -278,15 +281,18 @@ allprojects {
     //  - some tests (in particular js and binary-compatibility-validator depend on the fixed (default) location
     //  - idea seems unable to exclude common builddir from indexing
     // therefore it is disabled by default
-//    buildDir = File(commonBuildDir, project.name)
+    // buildDir = File(commonBuildDir, project.name)
 
+    val repos: List<String> by rootProject.extra
     repositories {
-        for (repo in (rootProject.extra["repos"] as List<String>)) {
-            maven { setUrl(repo) }
+        for (repo in repos) {
+            maven(repo)
         }
+
         intellijSdkRepo(project)
         androidDxJarRepo(project)
     }
+
     configureJvmProject(javaHome!!, jvmTarget!!)
 
     val commonCompilerArgs = listOf("-Xallow-kotlin-package", "-Xread-deserialized-contracts")

gradle.properties

@@ -4,6 +4,7 @@ org.gradle.configureondemand=false
 org.gradle.jvmargs=-Duser.country=US -Dkotlin.daemon.jvm.options=-Xmx1600m
 
 kotlin.compiler.effectSystemEnabled=true
+#maven.repository.mirror=http://repository.jetbrains.com/remote-repos/
 #bootstrap.kotlin.repo=https://dl.bintray.com/kotlin/kotlin-dev
 #bootstrap.kotlin.version=1.1.50-dev-1451
 #signingRequired=true