Fixed grid, preliminary styles and image resizing

- I have altered the grid classes to accommodate for the addition of
the sidebar
- (preliminary) I have added styles to connect the sidebar to the
header and extend its height on large screens
- (preliminary) I have added javascript code to resize the images to
fit on the page (this will be replaced by a server-side script to
handle image resizing based on device width and height)
- added bootstrap cdn instead of local files
- created initial backbone structure. Not active as of yet.