editable report item names, closes #38

beat/web/reports/migrations/0004_auto_20170410_1121.py

beat/web/reports/models.py

...eports/static/reports/app/directives/edit/addItemsMenu.js

...eb/reports/static/reports/app/directives/edit/plotItem.js

...b/reports/static/reports/app/directives/edit/tableItem.js

...eb/reports/static/reports/app/directives/edit/textItem.js

...eb/reports/static/reports/app/directives/view/plotItem.js

...b/reports/static/reports/app/directives/view/tableItem.js

...eb/reports/static/reports/app/directives/view/textItem.js