Make width flexible above 960px

Width of content was previously fixed at 960px. 960px is now the
minimum width, but if there is space the content will expand to
fill 90% of the browser window.

Note that the entry-meta position has also changed to be properly
floated, as this is easier to manage and fits in better.

Change-Id: I1b9d01a832d5191768edc1764cded4a4b57fe2b5
Merge "Make width flexible above 960px"