Fixed bug in Calendar tab. GET request method replaced with POST so w…

…hen a lot of project selected we don't get 414 Request-URI Too Large or php errors.

Improve tasks filter by project selector, add ability to unselect all

Small fix in Calendar

fix: links

Update .gitlab-ci.yml file

Merge branch '0-ureport' into 0-grant

New features & bug fixes.

New reports: 
- Planned Time
- Universal

Gantt chart
Improved comments (now include markdown)  + more advanced task change history
WebSocket for realtime update of some parts of the app
Attachments (Tasks, Comments)
Ability to disable screenshots
Improved error handling and display
Kanban
Dashboard now drawn with svg for better quality
Calendar
Project groups

Offline Sync:
Export Projects and tasks
Import Intervals/Screenshots


Mobile layout for:
Tasks: List,View,Edit;
Projects:List,View,Edit;
Login
Gantt

fix: screenshot upload

fix: roles

feat: update kaniko version