Avoid using reflected types in the scripting API

since it causes numerous classloading issues. Using the wrapping types
and reload them in the proper context when needed.
Note: this version supports only classes, but the wrapping type could
be extended to support other types in the future.
+ numerous fixes related to proper loading and handling of the templates.

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/K2JVMCompiler.kt

@@ -235,9 +235,11 @@ class K2JVMCompiler : CLICompiler<K2JVMCompilerArguments>() {
             if (!explicitOrLoadedScriptingPlugin) {
                 val libPath = paths?.libPath?.takeIf { it.exists() } ?: File(".")
                 with(PathUtil) {
-                    val jars = arrayOf(KOTLIN_SCRIPTING_COMPILER_PLUGIN_JAR, KOTLIN_SCRIPTING_COMMON_JAR, KOTLIN_SCRIPTING_JVM_JAR)
-                        .mapNotNull { File(libPath, it).takeIf { it.exists() }?.canonicalPath }
-                    if (jars.size == 3) {
+                    val jars = arrayOf(
+                        KOTLIN_SCRIPTING_COMPILER_PLUGIN_JAR, KOTLIN_SCRIPTING_COMMON_JAR,
+                        KOTLIN_SCRIPTING_JVM_JAR, KOTLIN_SCRIPTING_MISC_JAR
+                    ).mapNotNull { File(libPath, it).takeIf { it.exists() }?.canonicalPath }
+                    if (jars.size == 4) {
                         pluginClasspaths = jars + pluginClasspaths
                     }
                 }

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/plugins/PluginCliParser.kt

@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.compiler.plugin.*
 import org.jetbrains.kotlin.config.CompilerConfiguration
 import java.io.File
 import java.net.URL
+import java.net.URLClassLoader
 import java.util.*
 
 object PluginCliParser {