Improve Type Resolution

NOTE: This PR is not complete, but the test suite is passing. Looking for feedback. Also, it is based on #90, so that should be merged before this PR, or this PR should be rebased.

This PR aims to rework type resolution in BridJ, so that resolution code is off loaded to a third party library and to support more complex generics in classes extending StructObject. Once merged, the following struct will work with BridJ:

  public static abstract class AbstractStructField<S extends StructObject, T extends AbstractStructField<S, T>> extends StructObject {
    @Field(0)
    public S getStruct() {
      return io.getNativeObjectField(this, 0);
    }

    public T setStruct( S struct ) {
      io.setNativeObjectField(this, 0, struct);
      return (T)this;
    }
  }

  public static class StructOfInteger extends StructObject {
    @Field(0)
    public int getField() {
      return io.getIntField(this, 0);
    }

    public StructOfInteger setField( int field ) {
      io.setIntField(this, 0, field);
      return this;
    }
  }

  // this is the struct that will now work as expected.
  public static class NestedStructOfInteger
    extends AbstractStructField<StructOfInteger, NestedStructOfInteger> {}

Status: Code to support generic resolution has been introduced and a test called StructGenericsTest has been added to verify that structures of this type now work.

TODO: Remove dead code dealing directly with Java's type classes.

Build Changes:

The library supporting type resolution, ClassMate, is compiled for Java 1.6, so Java 1.5 compatibility has been abandoned.
The source version has been moved to 1.8 and Retrolambda has been introduced, to produce classes compatible with Java 6.
The version has been bumped to 0.8.0-SNAPSHOT, to reflect the changes in the resulting artifacts.

Fixes #59

nativelibs4java / BridJ

Improve Type Resolution #91