Merge branch '1373_more_filter_options'

Merge branch '1373_more_filter_options'

* 1373_more_filter_options:
  Update po/*.po files.
  Document new filter options.
  Load and save filter parameters.
  Implement more option for panel filter:
  Rename panel_select_flags_t -> select_flags_t.
  Handle CK_Filter command in the file panel level.
  Add macros for select/unselect histories.
  (panel_select_unselect_files_dialog): show error message if pattern is malformed.
  (mc_search_prepare): cache result.
  mc_search_struct: rename member: conditions -> prepared_conditions.
  Ticket #1373: add more options to "Filter" dialog window.