Modify to rotate log for development environment

config/environments/development.rb
- Modify to rotate log using Logger.
Refactor GeneralLogbookFilter to remove FIELD_OFFICE_ALL, etc.

app/models/general_logbook_filter.rb
- Remove FIELD_OFFICE_ALL and use an empty string instead in
  FIELD_OFFICE_SELECTION.
- Refactor to_be_filtered?() to just return whether corresponding
  attribute is present?.
- Add Rdoc for the constants and methods.
app/models/general_logbook.rb
- Add Rdoc for the constants and methods.
app/models/work_plan_filter.rb
- Add Rdoc for initialize().
'general_logbooks#index' to highlight search words

app/assets/stylesheets/style.css
- Add 'span.search_word'.
app/helpers/general_logbooks_helper.rb
- Modify displaying_value() to highlight search words in
  equipment and message.
app/models/general_logbook_filter.rb
- Add attr_reader :search_words and modify initialize() to
  prepare it from @full_text_search.
- Fix ARRAY_OF_RE_WRONG_USAGE_OF_OR to match whole word 'OR'.
'general_logbooks#index' to use white font for some logtype

app/assets/stylesheets/style.css
- Add "color: white" to '#table_logbooks td.Trouble' and
  '#table_logbooks td.Demands'.
Modify to rotate log for production environment

config/environments/production.rb
- Modify to rotate log for the environment.
config/unicorn-config.rb to specify worker_processes by Rails env

config/unicorn-config.rb
- Modify to specify the number of worker_processes according
  to Rails environment.
'general_logbooks#index' not to paginage when displaying for single day

app/controllers/general_logbooks_controller.rb
- Modify index() not to paginage @logbooks if
  @general_logbook_filter.num_rows_per_page is nil.
app/models/general_logbook_filter.rb
- Remove attr_reader :num_rows_per_page and add explicit method
  num_rows_per_page() to return nil if @date_from and @date_to
  are on same day.
app/views/general_logbooks/index.html.erb
- Modify to display "paginate @logbooks" only when @logbooks is
  paginated.
Add model AdHocWork

app/models/ad_hoc_work.rb
- Newly created.
app/models/datetimable.rb
- Modify datetime_end() to use COLUMN attribute finish_time
  if endtime does not exist.
Add default_scope to model AdHocWork

app/models/ad_hoc_work.rb
- Add default_scope.
Generate AdHocWorksController

app/controllers/ad_hoc_works_controller.rb
- Newly generated.
Add scope :has_start_time to model AdHocWork

app/models/ad_hoc_work.rb
- Add scope :has_start_time.
Add view 'ad_hoc_works#approval_status'

app/controllers/ad_hoc_works_controller.rb
- Add approval_status().
app/controllers/application_controller.rb
- Add clear_helpers() call.
app/helpers/ad_hoc_works_helper.rb
- Add displaying_value().
app/views/ad_hoc_works/approval_status.html.erb
- Newly created.
config/routes.rb
- Add resources route :ad_hoc_works with only collection route
  :approval_status.
'ad_hoc_works#approval_status' to display description for only first line

app/helpers/ad_hoc_works_helper.rb
- Modify displaying_value() to return first HTML line only
  when column_name is 'description'.
app/helpers/application_helper.rb
- Add first_line().
app/views/ad_hoc_works/approval_status.html.erb
- Display column indexes of the table.
config/locales/ja.yml
- Add "ad_hoc_work.{datetime_start,description} under
  "activerecord.attributes".
'ad_hoc_works#approval_status' to display field_office and approval

app/assets/stylesheets/style.css
- Add '#table_ad_hoc_works_approval_status td'.
- Add '#table_ad_hoc_works_approval_status .datetime_start', etc.
- Add '#table_ad_hoc_works_approval_status .Approved', etc.
app/controllers/ad_hoc_works_controller.rb
- Introduce COLUMN_NAMES_TO_DISPLAY_IN_APPROVAL_STATUS for the value
  of @column_names and add 'field_office' and 'approval' to it.
app/helpers/ad_hoc_works_helper.rb
- Modify displaying_value() to handle argument column_name of 'approval'.
- Add displaying_css_class().
app/views/ad_hoc_works/approval_status.html.erb
- Add HTML id to the table.
- Modify to use displaying_css_class() for HTML class of <td>'s.
config/locales/ja.yml
- Add "field_office" and "approval" under "activerecord.attributes.ad_hoc_work".
- Add "ad_hoc_work.approval.*" under "activerecord.values".
Add scope :before_finish_time to model AdHocWork for '#approval_status'

app/assets/stylesheets/style.css
- Split into '#table_ad_hoc_works_approval_status .Approved'
  and '#table_ad_hoc_works_approval_status .Finished'.
app/controllers/ad_hoc_works_controller.rb
- Modify approval_status() to use AdHocWork.before_finish_time
  to prepare @ad_hoc_works.
app/models/ad_hoc_work.rb
- Add scope :before_finish_time.