* improved 'indicator.views.follow_indicator()',
  renamed to 'indicator_fanduf()' due to name conflict
* finished 'search' function for page indicator NewDeleteIndex.html
* added 'apps/utils/search_tools.py': some tools to process search results
* renamed 'sciblog/templatetags/tools.py' to 'get_range.py'
* added 'format_data()' to indicator.tools': to format data of
  record/confine, make it properly display in html page;
* 'indicator/javascripts/new_delete_index.js':
  added global 'var added_indexes_id' to track the already added indexes
* added 'indicator/templatetags/divisible_by.py' filter to check
  if a number can be extactly divide by another number;
* fixed the 'index_card_fir/index_card_sec' problem of
  'act_card_container' of page 'SheetDefault.html'
* indicator/static/css/new_delete_index.css:
  added 'index_search_error' and 'index_error'

* fixed 'unit.dump' problems in 'indicator.models'
* 'indicator.tools':
  o added 'RI_TYPES', 'RI_WEIGHTS'
  o added 'type' in the return value of 'calc_indicator_weight()'
    and 'recommend_indicator()'
* added field 'followedHistories' in 'indicator.models.UserIndicator'
* moved 'follow_indicator()' and 'unfollow_indicator()' from
  'indicator.views' to 'indicator.tools'

TODO:
* highcharts: draw chart for indicator records;
* add/edit data, and submit (page format design)
* followed indicator submit buttion