This plugin allows a simple use of OR operator in query.

This plugin adds three new filters, acting as markers: All follow (OR), Any follow (AND), Any follow (OR)
Here is how it works

1. All the filters to be ANDed (if any) should come first. They will be joined with AND as usual. Lets call it A part, A can be empty
2. Then comes one of the Marker filters: All follow (OR), Any follow (AND), Any follow (OR), lets call it M
3. Then come other filters for example f1, f2, f3

The result will be 
A. If M is: All follow (OR) is Yes =>  (A) OR (f1 AND f2 AND f3)
            All follow (OR) is not Yes =>  (A) OR NOT (f1 AND f2 AND f3)
B. If M is: Any follow (AND) is Yes => (A) AND (f1 OR f2 OR f3)
            Any follow (AND) is not Yes => (A) AND NOT (f1 OR f2 OR f3)
C. If M is: Any follow (OR) is Yes =>  (A) OR (f1 OR f2 OR f3)
            Any follow (OR) is not Yes =>  (A) OR NOT (f1 OR f2 OR f3)

Notes:
1. It is possible to user more than one Marker in the query. What the term "follow" means is all the filters below till another marker or end.
2. This plugin is tested in Redmine 2.6.5, ruby 2, rails 3.2.2. By examining the code of statement method, I guest that it will work for 2.6.x, 3.0.3 (they all have the same statement method)

3. To help debug, I log the result of the statement method (with prefix STATEMENT) into log file at info level . You can exam this log to see if it works correctly

4. Here is the list of plugins that work with this plugin (in redmine 2.6.5, ruby 2, rails 3.2.2)
      a_common_libs
      advanced_membership_management
      due_date_reminder
      global_roles
      planner
      progressive_projects_list
      projects_treeview
      quick_edit
      quick_view
      recurring_tasks
      redmine__select2
      redmine_admin_monitor
      redmine_all_files
      redmine_app_notifications
      redmine_assets_plugin
      redmine_autowatch
      redmine_banner
      redmine_base_deface
      redmine_base_select2
      redmine_better_gantt_chart
      redmine_checklists
      redmine_custom_css
      redmine_custom_js
      redmine_custom_reports
      redmine_custom_workflows
      redmine_dashboard
      redmine_default_custom_query
      redmine_didyoumean
      redmine_digest
      redmine_dmsf
      redmine_drafts
      redmine_extended_spent_time
      redmine_graphs
      redmine_housekeeping
      redmine_impersonate_system
      redmine_importer
      redmine_improved_searchbox
      redmine_information
      redmine_issue_journal
      redmine_issues_sorting
      redmine_keyboard_shortcuts
      redmine_leaves
      redmine_lightbox2
      redmine_login_audit
      redmine_logs
      redmine_mail_reminder
      redmine_maintenance_mode
      redmine_mentions
      redmine_multiple_files_upload
      redmine_multiprojects_issue
      redmine_my_page_queries
      redmine_my_roadmaps
      redmine_pastebin
      redmine_people
      redmine_pipeline_plugin
      redmine_pivot
      redmine_planning
      redmine_questions
      redmine_redshares
      redmine_related_buster
      redmine_reorder_links_arbitrary
      redmine_role_replacements
      redmine_schedules
      redmine_silencer
      redmine_startpage
      redmine_stats
      redmine_status_history
      redmine_stealth
      redmine_subtasks_inherited_fields
      redmine_summed_fields
      redmine_tagging
      redmine_task_board
      redmine_theme_changer
      redmine_time_tracker
      redmine_timesheet_plugin
      redmine_track_control
      redmine_tweaks
      redmine_update_reminder
      redmine_user_issues
      redmine_watcher_groups
      redmine_workload
      rmplus_devtools
      sidebar_hide
      simple_author_change
      status_button
      stuff_to_do_plugin
      subscription

