Add link to user servey by Google Apps at page top

app/views/layouts/application.html.erb
- Add link to user servey by Google Apps.
lib/constant.yml
- Add Constant url_for_survey.
Alter GeneralLogbookFilter according to Yufutsu Plant unification

app/models/general_logbook_filter.rb
- Alter FIELD_OFFICE_SELECTION and H_FIELD_OFFICE_TO_AREA2_ARRAY
  according to Yufutsu Plant unification.
Emphasize link to user servey

app/assets/images/button_for_survey.png
- Newly added.
app/views/layouts/application.html.erb
- Enlarge the notice for user survey and use an image for
  the link.
Fix TaskPlan#name() to nil-check attribute sequence_order

app/models/task_plan.rb
- Fix name() to nil-check attribute sequence_order.
Correct WorkPlan#section_in_charge() for new sections in Yufutsu

app/models/work_plan.rb
- Correct SECTIONS for new sections created in the result of
  Yufutsu Plant merger.
config/locales/ja.yml
- Add new keys to "activerecord.values.work_plan.section_in_charge"
  for new sections created in the result of Yufutsu Plant merger.
Add 'Katakai' to drop-down list for field office

app/models/general_logbook_filter.rb
- Add FIELD_OFFICE_KATAKAI, and add corresponding entries to
  FIELD_OFFICE_SELECTION and H_FIELD_OFFICE_TO_AREA2_ARRAY.
Add selection for all field offices in Nagaoka to GeneralLogbookFilter

app/models/general_logbook_filter.rb
- Add FIELD_OFFICE_SHIUNJI, FIELD_OFFICE_NIIGATA, FIELD_OFFICE_MITSUKE,
  FIELD_OFFICE_MISHIMA and FIELD_OFFICE_YOSHII.
- Add entires for the above to FIELD_OFFICE_SELECTION and
  H_FIELD_OFFICE_TO_AREA2_ARRAY.