Reorder columns of source-browser

I was looking at the source browser, and I think the order of the columns is a bit inconsistent.

On one hand, we have a "right to left" approach for maturity of language paris, with incubator at the rightest position (taking into account only langpairs), and then getting more mature as we move left (trunk <- staging <- nursery <- incubator).

But the inconsistency comes outside the language pairs. At the very left we have "languages", that we could consider "as stable as trunk", which could make sense. But then "apertium-tools" is at the very right. "more unstable than incubator".

So my proposal would be to have tools closer to trunk. But as this could be achieved in different ways, I wanted to start a conversation to see what other people think.

Possible options:

1. Move apertium-tools to the very left
- `tools -> languages -> trunk -> staging -> nursery -> incubator`
1. Change the order of colums to be left-to-right, so we have
- `incubator -> nursery -> staging -> trunk -> languages -> tools`
1. Replace tools and languages (with maturity going LTR or RTL)
- I don't think considering "languages" to be "before" incubator is wrong, but this could be controversial, an maybe confusing to other people. In any case, this is how I've always thought about the different stages, and how I would have implemented this.
- `languages -> incubator -> nursery -> staging -> trunk -> tools`

Thoughts?