Constructor id arguments don't need to be listed first

[Condor70]

I was working on using MyBatis with pre-existing classes and i ran into the problem that according to the DTD idArgs need to come before args in the constructor.

This following example doesn't validate, although MyBatis doesn't actually have this restriction:

<resultMap id="MyClass" type="test.MyClass">
	<constructor> <!-- Error: The content of element type "constructor" must match "(idArg*,arg*)". -->
		<arg column="name" javaType="string" />
		<idArg column="id" javaType="string" />
	</constructor>
</resultMap>

Can mybatis-3-mapper.dtd be changed from:
<!ELEMENT constructor (idArg*,arg*)>
to
<!ELEMENT constructor ((idArg|arg)*)>

[Condor70]

I just noticed that MyBatis has an XSD as well, which also would need to change:

Current mybatis-mapper.xsd:

<xs:element name="constructor">
	<xs:complexType>
		<xs:sequence>
			<xs:element minOccurs="0" maxOccurs="unbounded" ref="idArg"/>
			<xs:element minOccurs="0" maxOccurs="unbounded" ref="arg"/>
		</xs:sequence>
	</xs:complexType>
</xs:element>

New mybatis-mapper.xsd:

<xs:element name="constructor">
	<xs:complexType>
		<xs:choice minOccurs="0" maxOccurs="unbounded">
			<xs:element ref="idArg"/>
			<xs:element ref="arg"/>
		</xs:choice>
	</xs:complexType>
</xs:element>

[harawata]

Hello @Condor70 ,

I didn't know this was possible with DTD.
Would you send us a PR?
If you are busy, please just let me know and I'll take care of it later.

FYI, if you specify name, the order of idArg/arg does not matter.
See #721