Build kotlin-reflect.jar in build.xml and for Maven

Reflection will be distributed in a separate jar and not in kotlin-runtime.jar
for two primary reasons:
- Reflection implementation at the moment takes almost 2Mb
- Separate libraries for separate features is a technique encouraged by Maven,
  and it's inconvenient to make it different in the compiler distribution

core/runtime.jvm/src/kotlin/jvm/KotlinReflectionNotSupportedError.java

@@ -18,7 +18,6 @@ package kotlin.jvm;
 
 public class KotlinReflectionNotSupportedError extends Error {
     public KotlinReflectionNotSupportedError() {
-        super("Kotlin reflection implementation is not found at runtime. " +
-              "Make sure you do have kotlin-runtime.jar and do not have kotlin-runtime-minimal.jar in the classpath");
+        super("Kotlin reflection implementation is not found at runtime. Make sure you have kotlin-reflect.jar in the classpath");
     }
 }