Issue #736066 by droplet, drpal, vaplas, dmsmidt, effulgentsia, nod_, tic2000,...

Issue #736066 by droplet, drpal, vaplas, dmsmidt, effulgentsia, nod_, tic2000, tim.plunkett, lauriii, casey, morsok, idebr, alexpott, yched, tedbow, GuyPaddock, drintios, edurenye, dtamajon, adinac, VinayLondhe, ajalan065, hrmoller, ericduran, piyuesh23, andreyks, roborew, Wim Leers, lokapujya, samuel.mortenson, Dries, DuaelFr, OnkelTem, manu manu, khiminrm, Greg Boggs, SKAUGHT, itsekhmistro, fubhy, SpadXIII, s.messaris, zviryatko: ajax.js insert command sometimes wraps content in a div, potentially producing invalid HTML and other bugs