添加 IRow 接口，支持统一的方式来处理 Model 和 Record

src/main/java/com/jfinal/plugin/activerecord/IRow.java

@@ -0,0 +1,104 @@
+package com.jfinal.plugin.activerecord;
+
+import java.math.BigDecimal;
+import java.time.LocalDateTime;
+import java.util.Map;
+
+/**
+ * IRow 支持统一的方式来处理 Model 和 Record
+ * 
+ * 例如可以用 List<IRow> 同时接收 List<Model> 与 List<Record> 变量并处理
+ */
+public interface IRow<M> {
+
+    public Map<String, Object> toMap();
+
+    public M put(Map<String, Object> maps);
+
+    public M set(String attr, Object value);
+
+    public <T> T get(String column);
+
+    /**
+     * Get column of any mysql type. Returns defaultValue if null.
+     */
+    public <T> T get(String column, Object defaultValue);
+
+    /**
+     * Get column of mysql type: varchar, char, enum, set, text, tinytext, mediumtext, longtext
+     */
+    public String getStr(String column);
+
+    /**
+     * Get column of mysql type: int, integer, tinyint(n) n > 1, smallint, mediumint
+     */
+    public Integer getInt(String column);
+
+    /**
+     * Get column of mysql type: bigint
+     */
+    public Long getLong(String column);
+
+    /**
+     * Get column of mysql type: unsigned bigint
+     */
+    public java.math.BigInteger getBigInteger(String column);
+
+    /**
+     * Get column of mysql type: date, year
+     */
+    public java.util.Date getDate(String column) ;
+
+    public LocalDateTime getLocalDateTime(String column);
+
+    /**
+     * Get column of mysql type: time
+     */
+    public java.sql.Time getTime(String column);
+
+    /**
+     * Get column of mysql type: timestamp, datetime
+     */
+    public java.sql.Timestamp getTimestamp(String column);
+
+    /**
+     * Get column of mysql type: real, double
+     */
+    public Double getDouble(String column);
+
+    /**
+     * Get column of mysql type: float
+     */
+    public Float getFloat(String column);
+
+    public Short getShort(String column);
+
+    public Byte getByte(String column);
+
+    /**
+     * Get column of mysql type: bit, tinyint(1)
+     */
+    public Boolean getBoolean(String column);
+
+    /**
+     * Get column of mysql type: decimal, numeric
+     */
+    public BigDecimal getBigDecimal(String column);
+
+    /**
+     * Get column of mysql type: binary, varbinary, tinyblob, blob, mediumblob, longblob
+     * I have not finished the test.
+     */
+    public byte[] getBytes(String column);
+
+    /**
+     * Get column of any type that extends from Number
+     */
+    public Number getNumber(String column);
+
+    /**
+     * Return json string of this record.
+     */
+    public String toJson();
+}
+