Patch Set 3:

ok, this looks better

I found a use case where "select all" / "deselect all" would be more useful than "toggle selection":

Suppose I have 17 repos in the list and 8 are already checked, now I want to just search one repo which is not yet selected, toggle selection is not useful here as it would select the 9 repos which weren't selected previously, so I need to click a lot of check boxes to reach what I want.
In this case the cheapest path would require 9 clicks (deselect 8 and select one).

Using "deselect all" button I could reach what I want with just 2 clicks.

Hence I would vote for replacing the "toggle selection" by "select all" / "deselect all" buttons, this pattern is also used in import projects wizard.