Added /task view and template. Also tweaked model to make doer and requester relationships.
#19: Added task statuses and buttons to start/complete/accept/reject tasks.
#19: Added links to tasks from the task list
#19: Added buttons to task list view that allows for filtering todo tasks, assigned tasks, and completed tasks
Added logs to tasks and made the logs editable (but only for the doer of the given task).
#19: Made descriptions of tasks editable (but only for the requester of the given task).
#19: Allowed for the title of a task to be edited, and added a page to create tasks. I think this closes #19
Merged master with the tasks branch. Closes #19.