Fixed bugs, cleanup, added info to data.json

  * Fixed a bug (return instead of next)
  * Added more output formats for cron job
  * Cleaning up output directory before running cron job
  * Added running time(start, end, duration) to data.json that is
    generated by PageViews::View::JSON
  * Cleanup uf unused files (deleted Model.pm , ParallelModel.pm
                             WikistatsColorRamp.pm, test.pl ,
                             test-parallel.pl , pageviews-parallel.pl)

Change-Id: I454b1947dcb9b6e4bbfbb17c49f9e6e231de4e95