Increment list counter in project view

This fixes a bug where if you have fewer than 10 projects, your top 10
projects were listed as:

6 - n/a (n/a)
6 - n/a (n/a)
6 - n/a (n/a)
6 - n/a (n/a)

rather than

7 - n/a (n/a)
8 - n/a (n/a)
9 - n/a (n/a)
10 - n/a (n/a)
Don't link to null projects

If you have fewer than 10 projects, then empty running projects were
linked to with the path `/projects/-1`.

Copy/pasted the list strategy from the other project sections in the
same partial so the duplication becomes explicit.
Simplify stats projects view

Use `each_with_index` instead of hand-wrought index to loop through
projects, and use a partial for the duplicated empty list items.
Collapse duplication in stats project view
Merge pull request #163 from kytrinyx/stats-project-view

Simplify stats project view