updated jquery version to 1.8.1

Dependencies

• [2] YQWH4POV * Simplify.
• [3] T4LLYESZ * Nix expression for building Hydra.
• [4] F3GR3UC5 * Actually, include jquery and tablesorter in the source tarball.

Change contents

• replacement in release.nix at line 21
  [2.347]→[2.347:491](∅→∅)
  − url = http://jqueryui.com/download/jquery-ui-1.7.2.custom.zip;

  − sha256 = "1l9dwaaqvdysmzlkg1vb8j0s0xn63d475gh53pjjwxw85668krdh";
  [2.347]

  [2.491]
  + url = http://jqueryui.com/download/jquery-ui-1.8.1.custom.zip;

  + sha256 = "0r4hgb0dl7xavkxllybmmvshxh383sh8lyczfas544bcfy4wj9f8";