Fix areaMode=stacked with drawAsInfinite()
Fix areaMode=stacked with drawAsInfinite()

Another messy edge case. Closes #31

evernote/graphite-web,Krylon360/evernote-graphite-web,evernote/graphite-web,Krylon360/evernote-graphite-web,Krylon360/evernote-graphite-web,evernote/graphite-web,Talkdesk/graphite-web,evernote/graphite-web,Krylon360/evernote-graphite-web,Talkdesk/graphite-web,Talkdesk/graphite-web,Talkdesk/graphite-web,evernote/graphite-web,Talkdesk/graphite-web,Krylon360/evernote-graphite-web,Talkdesk/graphite-web,Krylon360/evernote-graphite-web