Test files path and extra files path

<tool id="composite_output_tests" name="composite_output_tests" version="1.0.0">

  <!-- command mixes files_path and extra_files_path, both shuold work -->

  <command>

    mkdir '$output.extra_files_path';

    mkdir '$output.extra_files_path/output';

    cp '$input.extra_files_path'/* '$output.extra_files_path';

    echo "1 2 3" > '$output.extra_files_path/md5out';

    mkdir '$output.files_path';

    mkdir '$output.files_path/output';

    cp '$input.extra_files_path'/* '$output.files_path';

    echo "1 2 3" > '$output.files_path/md5out';

    echo "1" > '$output.extra_files_path/output/1';

  </command>

  <inputs>