Added legend in graph view to display addition info.

Shows the team name and the color of its corresponding nodes in the
network graph. Also has a field for the current score, but does not
update (yet).
Made scores in legend update with each iteration.
Created uploads folder for team when registered.

Rather than waiting for when the team submits for a graph, simply
create a new folder in `private/uploads` with the corresponding team
name.

Also needed to restrict usernames to alphanumeric symbols (includes
underscore as well).
No need to try and create directory for submission.

Able to assume was already created when team was registered.
Created dashboard view for submissions.

Displays all runs in a table with teams along the rows and graphs
across the columns. If the team has played on a particular graph, then
a link will be present that shows the cascade.
Added graph categories into heading of submission table.
Handle case where no teams or graphs are present.
Fixed issue where had changed collection to runs.