Fixing performance issue in multiview gallery for rendering large data sets

Updated the multiview gallery example's css to use display:inline-block; rather than float: left for positioning grid items.  As reported in #882 when a large dataset is used the browser starts to behave unpredictable due to a performance differences.

I couldn't reproduce the issue described in #882.  But when using float to render a data set of 8000 items it took almost a minute on Chrome.  Display: inline-block rendered instantly by comparison.