Merge branch '3607_cleanup'

Merge branch '3607_cleanup'

* 3607_cleanup: (43 commits)
  Replace obsolete `INTLLIBS` with `LIBINTL` for `libmc`
  filehighlight: add more common file formats
  Move definition of reset_hp_softkeys variable to lib/tty/tty-slang.[ch].
  (feed_subshell): change type of fail_on_error from int to gboolean.
  Sync with gnulib 6ed53f13bc39d9a0252549e98a2a59441fb2351f.
  lib/widget/input_complete.c: apply coding guidelines.
  (command_completion_function): cleanup cppcheck warning.
  (dview_save_options): clarify boolean options.
  Get rid of global variables mc_main_config and mc_panels_config.
  (mc_realpath): cleanup cppcheck warning.
  (update_split): cleanup cppcheck warning.
  lib/vfs/direntry.c: cleanup cppcheck warnings.
  (mc_shell_get_installed_in_system): fix description.
  Fix typo.
  Clarify type cast in tgetsrt() calls.
  Clarify type cast in SLtt_tgetsrt() calls.
  MidnightCommander/mc#95: update Java syntax: add missing keywords: _ assert strictfp.
  MidnightCommander/mc#89: add webp extension to file highlight and extension files.
  MidnightCommander/mc#97: src/filemanager/mountlist.c: add makedev() declaration.
  (dlg_set_top_or_bottom_widget): move to proper file section.
  ...