implemented responsive image for #26
now using utils when possible for #23
product object now contains link, desc and key even in light forms (brands & categories pages)
brand and category pages are now more efficient, and use thumbnail lists for better design
finished beta product page, closes #23
recreating navbar for #24:
  - changed main css colors and organization
  - now using brands from db, corrected getNavbarBrands for the occasion
  - use a fixed-top navbar, coz it's so cool!
  - TODO: add categories from db
corrected urgent product filler bug: #29
now using latest bootstrap v3.1.1, closes #25
added categories in dropdown menu, #24
corrected urgent product filler bug: #29
added html option to link_to
corrected refresh navbars to keep all the categories
finished navbar with submenus, closes #24
Merge branch 'develop' into staging