Code review comment for lp:~sergei.glushchenko/percona-xtrabackup/20-bug856400

Hi Alexey,

* changes
  - rebased on latest trunk
  - typo in cleanup_dir_recursively fixed
  - bug reference in the test case comments fixed
  - added error handling for unlink
  - removed restart of server in testcase
  - parse innodb_data_file_path to avoid copying of
    system tablespace
* other things
  - there was a need for "\/+"
    because otherwise lines 50-52 wont give expected result
  - lines 50-52 were needed to restrict copying of contents of
    top level of datadir; now it is not needed as I start using
    value of innodb_data_file_path to prevent copying of
    system tablespace
  - I will never configure my text editor to highlight long lines, thanks;
    this is not a good place to discuss text editors and their settings
  - I think to have a possibility to pass user argument to callback
    is always a good idea, no matter whether this needed at the
    moment or not; but I changed the code to get rid of check_newer
* Jenkins
  - http://jenkins.percona.com/view/XtraBackup/job/percona-xtrabackup-2.0-param/393/

Thanks,
Sergei