0.6.6 allows composing plans from multiple files

It's fairly common to have information needed for a plan that you would like to reuse across multiple plans. For instance, if you are diff'ng DB sources, it would be nice to isolate the DB connection information to one file that could be reused across different comparisons.

0.6.6 now allows this via the -planfiles argument. -planfiles can take as a value either a single file name or multiple comma separated file names. It then composites the files to create a single plan. Here's an example:

 joe$ java -jar diffkit-app.jar -planfiles test3.plan.xml,sources.xml  

file: test3.plan.xml
...

      <bean id="plan" class="org.diffkit.diff.conf.DKPassthroughPlan">  
           <property name="lhsSource" ref="lhs.source" />  
           <property name="rhsSource" ref="rhs.source" />  
           <property name="sink" ref="sink" />  
           <property name="tableComparison" ref="table.comparison" />  
      </bean>  

file: sources.xml
...

      <bean id="rhs.source" class="org.diffkit.diff.sns.DKFileSource">  
           <constructor-arg index="0"  
                value="./test3.rhs.csv" />  
           <constructor-arg index="1" ref="lhs.table.model" />  
           <constructor-arg index="2">  
                <null />  
           </constructor-arg>  
              <constructor-arg index="3">  
                <null />  
              </constructor-arg>  
              <constructor-arg index="4" value="\," />  
              <constructor-arg index="5" value="true" />  
              <constructor-arg index="6" value="true" />  
      </bean>  

Note that the bean id="rhs.source" is nowhere defined in the file test3.plan.xml. It's only defined in the file sources.xml