Add new icons to menus and toolbar

- added new icons to menus and toolbar
Added locales for toolbar text.
Merge branch 'dev' into feature/new-icons

Conflicts:
	app/assets/stylesheets/fonts/_openproject_icon_font.sass
	public/templates/work_packages.html
	public/templates/work_packages/column_context_menu.html
removes task form i18n

We shouldn't introduce the new word of task, event if it just a temporary fix
Fixed info icon in table

- fixed font-color and underlining for info icon in table
Showing/hiding display sums icon.
Merge pull request #1373 from opf/bugfix/workpackage-table

Fixed info icon in table
Merge pull request #1371 from opf/fix/7995-toolbar-locales

Added locales for toolbar text.
Merge branch 'dev' into feature/new-icons

Conflicts:
	public/templates/work_packages.html
align menu items without icon

should be replaced by icon later
Merge pull request #1370 from opf/feature/new-icons

Add new icons to menus and toolbar
remove branches from .travis.yml

It is too hard to run travis on forked repositories.
It disturbs pull request process.

travis does not run Pull Request.

https://github.com/opf/openproject/pull/1338#issuecomment-44260428