implement Relation#upsert()

[gfx]

Resolve #294 by adding a new Relation#upsert() method.

Because this is a high-level method, it is defined in Relation, not in OrmaDatabase.

Also deprecates Relation#upserter() because it is very confusing. Use #inserter(OnConflict.REPLACE) if you know what to do.

---

the initial, generic version of #upsertWithoutTransaction():

@SuppressWarnings("unchecked")
@NonNull
public <PK> Model upsertWithoutTransaction(@NonNull final Model model) {
    Schema<Model> schema = getSchema();

    ContentValues contentValues = new ContentValues();

    for (ColumnDef<Model, ?> column : schema.getColumns()) {
        if (column.isPrimaryKey() && column.isAutoValue()) {
            // nothing to do
        } else if (column instanceof AssociationDef) {
            Object newAssociatedModel = updateOrInsertForAssociation(((AssociationDef) column).associationSchema,
                    column.get(model));
            schema.putToContentValues(contentValues, (ColumnDef) column, newAssociatedModel);
        } else if (column.type instanceof ParameterizedType
                && ((Class<?>) ((ParameterizedType) column.type).getRawType()).isAssignableFrom(SingleAssociation.class)) {
            SingleAssociation<?> assoc = (SingleAssociation<?>) column.get(model);
            Object newAssociatedModel = updateOrInsertForAssociation((Schema) Schemas.get(assoc.get().getClass()),
                    assoc.get());
            schema.putToContentValues(contentValues, (ColumnDef) column, SingleAssociation.just(newAssociatedModel));
        } else {
            schema.putToContentValues(contentValues, (ColumnDef) column, column.get(model));
        }
    }

    ColumnDef<Model, PK> primaryKey = (ColumnDef<Model, PK>) schema.getPrimaryKey();

    if (hasInitializedPrimaryKey(primaryKey, model)) {
        int updatedRows = updater()
                .where(primaryKey, "=", primaryKey.getSerialized(model))
                .putAll(contentValues)
                .execute();

        if (updatedRows != 0) {
            return model;
        }
    }

    long rowId = conn.insert(schema, contentValues, OnConflict.NONE);
    return conn.findByRowId(schema, rowId);
}

private <M> boolean hasInitializedPrimaryKey(ColumnDef<M, ?> primaryKey, M model) {
    return primaryKey.get(model) != null
            && (!primaryKey.isAutoValue() || ((Number) primaryKey.get(model)).longValue() != 0);
}

private <T> Object updateOrInsertForAssociation(Schema<T> associatedSchema, T model) {
    return associatedSchema.createRelation(conn).upsertWithoutTransaction(model);
}