[web2py] plupload and web2py

[mr.freeze]

I just spent the last hour tracking down a conflict between plupload
and web2py. Long story short: plupload.flash.js tags a div with a
secondary class 'flash' which web2py hides inadvertently in base.css,
thereby disabling the flash functionality of plupload. Just wanted to
document this in case it helps someone and also recommend that the
web2py 'flash' div be renamed to web2py_flash.