Rename jet -> kotlin in descriptor.loader.java, frontend.java

Split package 'lang/resolve/java' into two semantically different packages:
'resolve/jvm' and 'load/java'. Also rename 'lang/resolve/kotlin' to
'load/kotlin'

compiler/tests/org/jetbrains/kotlin/cli/CliCommonTest.java

@@ -16,7 +16,7 @@
 
 package org.jetbrains.kotlin.cli;
 
-import org.jetbrains.jet.lang.resolve.java.PackageClassUtils;
+import org.jetbrains.kotlin.load.kotlin.PackageClassUtils;
 import org.jetbrains.kotlin.name.FqName;
 import org.junit.Assert;
 import org.junit.Test;