Fix the x-axis to always default to the full set of commits.

This also does the same for shortcuts, would should make Alerts that are really tests beginning or ending more obvious.

BUG=skia:

Review URL: https://codereview.chromium.org/657123002
Display a message in the cluster status when the user is not logged in.

BUG=skia:

Review URL: https://codereview.chromium.org/655313002