Removing projects field from component view and filtering the activities...

... and milestones by project when creating task from component view + bugfix

* When creating task from a project, project field should not show and the activities, milestones should be filtered list for that project.
* bugfix in change_password
It does work, I wouldnt have pushed the code without testing. 
s3db.project_task_milestone.milestone_id.requires and s3db.project_task_activity.activity_id.requires are IS_ONE_OF objects. They do filter the activities and milestones.