Use teaserlist

[tuengominh]

Hi @viktorsmari

This closes issue #40

Yes, we can just use 'teaserlist' instead of both. Actually, it's better since many posts don't have file name value for 'teaserlatest'.

I also create a new template, change the field name to "Featured Image" and made the template default whenever users create a new post on Forestry.

Thanks

[viktorsmari]

@tuengominh What would then happen when viewing the file:

https://github.com/fablabbcn/fablabbcn-web/blob/master/_posts/events/2016-05-02-popkalab.md

Which has different teaserlist and teaserlatest ?