Add runtime-info to runs

[giuseppec]

For instance http://www.openml.org/r/477080 contains time infos:

We measure the training time, testing time and the total sum:

    <oml:evaluation>
      <oml:name>usercpu_time_millis_testing</oml:name>
      <oml:flow>openml.evaluation.usercpu_time_millis_testing(1.0)</oml:flow>
      <oml:value>452.4029</oml:value>
    </oml:evaluation>
    <oml:evaluation>
      <oml:name>usercpu_time_millis_training</oml:name>
      <oml:flow>openml.evaluation.usercpu_time_millis_training(1.0)</oml:flow>
      <oml:value>332999.7346</oml:value>
    </oml:evaluation>
    <oml:evaluation>
      <oml:name>usercpu_time_millis</oml:name>
      <oml:flow>openml.evaluation.usercpu_time_millis(1.0)</oml:flow>
      <oml:value>333452.1375</oml:value>
    </oml:evaluation>

You can also upload the cputime per CV fold:

    <oml:evaluation repeat="0" fold="0">
      <oml:name>usercpu_time_millis_testing</oml:name>
      <oml:flow>openml.evaluation.usercpu_time_millis_testing(1.0)</oml:flow>
      <oml:value>46.8003</oml:value>
    </oml:evaluation>
    <oml:evaluation repeat="0" fold="0">
      <oml:name>usercpu_time_millis_training</oml:name>
      <oml:flow>openml.evaluation.usercpu_time_millis_training(1.0)</oml:flow>
      <oml:value>204439.3105</oml:value>
    </oml:evaluation>
    <oml:evaluation repeat="0" fold="0">
      <oml:name>usercpu_time_millis</oml:name>
      <oml:flow>openml.evaluation.usercpu_time_millis(1.0)</oml:flow>
      <oml:value>204486.1108</oml:value>
    </oml:evaluation>