* [wip] added frappe/gantt

* frappe/gantt

[gantt] added view modes

[gantt] added vertical grid, view modes fixed

[gantt] fix bar_onclick

[gantt] fix view_mode rendering

[gantt] drag, resize gantt bar

[gantt] fixed month view

[gantt] separate styling

[gantt] save on datechange, progress field added

[gantt] fixed drag to snap on week/month