improve transitions for hovercat drop-down menu at desktop width (bug 1096654)
Added recommendation opt-out (bug 1072637)
fix `window.performance.now` polyfill (bug 1090572)
Merge pull request #787 from cvan/fix-performance-polyfill

fix `window.performance.now` polyfill (bug 1090572)
Merge pull request #784 from cvan/nav-hovercat-transitions

improve transitions for hovercat drop-down menu at desktop width (bug 1096654)
Merge branch 'master' of github.com:mozilla/fireplace
Commit from Mozilla Verbatim by user tonnes.mb@gmail.com.: 335 of 335 strings translated (0 fuzzy).
replace isotope (100KB) with salvattore (5KB) for feed layout (bug 1092331)