Refactor styling of the repository index page

The repository index page needed a bit overhauling. The navigation panel
at the bottom has now a bit wider. The important change here is that the
pane content can contain more than just one single dashboard.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Add map control to toggle scores in the future

I have added a custom control for the Leaflet map and styled it a bit. I
want to use the button action to toggle between two different marker
styles. Simple markers and markers that visualize the repository score.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Create custom marker to visualize snapshot scores

I have created a new custom marker to implement the score visualization
on the map. There are four different classes to map different score
categories: unknown, low, medium and high.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Encapsulate repository map code into a class

For better abstraction and accessibility of map functions I have
refactored the whole code into its own class.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Implement toggle button for score visualization

The score visualization can now be toggled on the repository map.
Another feature has been shipped.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Rename link checker and license metric

I have renamed the link checker and license metric to more general terms
that use the quality factor they are describing: openness and
availability.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Implement ETA display for the scheduler

Another column has been added to the scheduler table. After a step is
made, the estimated time of arrival, respectively estimated time until
termination is calculated. This is now refreshed as well, when the
status is requested.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>