tasks.tcl

Many many updates:

Added in basic notifications (no UI) for when tasks are created

Reduced the number of pages required for task create from 3 to 2 when dependencies
are being created.

Set up ability to add dependencies between newly created tasks (checks for loops so
they don't depend on each other)

Finished adding in basic categorization. UI could be improved, but it works.

Many minor UI updates.

Added in some functions that I had neglected to commit earlier.

Note that this still has a bug in the all_users view. It should be all_users_all, I
believe.