Rework compiler dependency management

And support for searching them locally and
downloading from internal server if KONAN_USE_INTERNAL_SERVER is set

Also:
Allow sysroot to change version minorly.

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Distribution.kt

@@ -52,15 +52,8 @@ class Distribution(val targetManager: TargetManager,
     val dependenciesDir = DependencyProcessor.defaultDependenciesRoot.absolutePath
 
     val targetProperties = KonanProperties(target, properties, dependenciesDir)
-    val hostProperties = if (target == host) {
-        targetProperties 
-    } else {
-        KonanProperties(host, properties, dependenciesDir)
-    }
-    val dependencies = targetProperties.dependencies
 
-    val llvmHome = hostProperties.absoluteLlvmHome
-    val hostSysRoot = hostProperties.absoluteTargetSysRoot
+    val llvmHome = targetProperties.absoluteLlvmHome
     val llvmBin = "$llvmHome/bin"
     val llvmLib = "$llvmHome/lib"
     val llvmLto = "$llvmBin/llvm-lto"

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanConfig.kt

@@ -54,7 +54,7 @@ class KonanConfig(val project: Project, val configuration: CompilerConfiguration
 
     private fun Distribution.prepareDependencies(checkDependencies: Boolean) {
         if (checkDependencies) {
-            DependencyProcessor(java.io.File(dependenciesDir), targetProperties).run()
+            targetProperties.downloadDependencies()
         }
     }
 

backend.native/konan.properties

@@ -17,6 +17,9 @@
 # TODO: Do we need a $variable substitution mechanism here?
 dependenciesUrl = https://download.jetbrains.com/kotlin/native
 
+# In order of preference:
+dependencyProfiles = default alt
+
 # Don't check dependencies on a server.
 # If true, dependency downloader will throw an exception if a dependency isn't found in konan.home.
 airplaneMode = false