Integrated Gallery into DataCultures: images and videos load properly

https://jira.ets.berkeley.edu/jira/browse/CYB-80

Initial integration of Gallery into DataCultures

Styling will be completely revamped by @ericayin, at the moment only functionality is of core value
Indentation in this file looks a little screwy. Nit picky: you added unnecessary space in front of Default.