Fixes for 2.1.0beta1:

Fixes for 2.1.0beta1:

* The CSS definition has been removed from the config.pl file and
  is now a separate file, BackupPC_stnd.css.  A new config variable,
  $Conf{CgiCSSFile}, gives the name of the CSS file to use.
  Suggested by Ender Mathias.

* Fixed the filling of the host name select box for admins.
  The default $Conf{CgiNavBarAdminAllHosts} is now 1.
  Reported by Doug Lytle.

* Cleaned up warning message for restore using rsync when checksum
  caching is on, but when file didn't have cached checksums.

* Fixed BackupPC_archiveHost to support par2 (par2cmdline).
  Patch submitted by Jaco Bongers and adapted by Josh Marshall.

* Improved stat() usage in BackupPC_nightly, plus some other cleanup,
  giving a significant performance improvement.  Patch submitted by
  Wayne Scott.

* Allow several BackupPC_nightly processes to run in parallel based
  on new $Conf{MaxBackupPCNightlyJobs} setting.  This speeds up the
  traversal of the pool, reducing the overall run time for
  BackupPC_nightly.

* Allow BackupPC_nightly to split the pool traversal across several
  nightly runs.  This improves the running time per night, at the expense
  of a slight increase in disk storage as unused pool files might not
  be deleted for a couple of days.  Controller by new config setting
  $Conf{BackupPCNightlyPeriod}.