Merge branch '2876_cleanup'
* 2876_cleanup:
Update EN and RU man pages: add missing options.
fixed doxygen documentation
fixed doxygen.cfg, excluded directory /tests/ from doxygen path's
removed obsolete params from edit_push_undo_action/edit_push_redo_action
Ticket #2861: additional error handling in edit_save_block().
(str_utf8_normalize): ret rid of extra memory allocation.
Use g_strndup() instead of g_strdup()
(get_absolute_name): missing finish NULL in vfs_path_append_vpath_new() call.
(edit_do_undo): cleanup of labeled statement usage.
Fix mouse event handling in menu that overlaps buttonbar.
mcdiffview: code cleanup and cosmetics.
Reorder checks in configure.ac.
Cleanup of screen library detection m4 code.
Refactoring of many conditions.
(edit_do_search): refactoring of search loop condition.
Avoid double checks of bookmarks in editor.
Ticket #2876: code cleanup before 4.8.6 release.