Merge pull request #25 from msp4/buttons

Buttons
added filters in researches
added icon loading in create research
update research filters
Fix #17
added tooltip in list vacancies
Fixed #23
renamed research menu
added api for frozen balance
update offers.server.controller.js
Fixed #26
added templates certificates and templates worksheets
added message if empty templates
update researches.server.controller.js
updated the validation in research
added accepting the offers when vacancies are inactive
added API to view legend
update worksheet-viewer.client.view.html
update worksheet-viewer.client.view.html
added information about shoppers in dashboard