Delete almost all code related to signature writing

Delete org.jetbrains.jet.rt.signature and jet.typeinfo packages from runtime,
refactor BothSignatureWriter so that it now writes only java generic signature
and saves parameter types and kinds

compiler/frontend/src/org/jetbrains/jet/lang/descriptors/TypeParameterDescriptor.java

@@ -27,6 +27,7 @@ import java.util.Set;
 public interface TypeParameterDescriptor extends ClassifierDescriptor {
     boolean isReified();
 
+    @NotNull
     Variance getVariance();
 
     @NotNull

compiler/frontend/src/org/jetbrains/jet/lang/descriptors/impl/TypeParameterDescriptorImpl.java

@@ -124,6 +124,7 @@ public class TypeParameterDescriptorImpl extends DeclarationDescriptorNonRootImp
     }
 
     @Override
+    @NotNull
     public Variance getVariance() {
         return variance;
     }

compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/descriptors/AbstractLazyTypeParameterDescriptor.java

@@ -97,6 +97,7 @@ public abstract class AbstractLazyTypeParameterDescriptor implements TypeParamet
         return reified;
     }
 
+    @NotNull
     @Override
     public Variance getVariance() {
         return variance;