Fixed wrong start project date + Some CSS adjustments
Merge branch 'master' of https://github.com/loispuig/redmine_dhtmlx_gantt

* 'master' of https://github.com/loispuig/redmine_dhtmlx_gantt:
  Update README.md
  Doc : permissions screenshot
  Update README.md
  Update README.md
  Rename README.rdoc to README.md