Remove use of the deprecated $.curCSS

[adamgriffis]

$.curCSS was dropped in 1.8 - since 1.3 curCSS has just been an alias for $.css, so it is safe to just replace curCSS with css:

http://blog.jquery.com/2012/08/09/jquery-1-8-released/

[dncrht]

There's no need for the workaround.
You can remove the whole line, as the variable oldDisplay is not being used at all.

[heathdutton]

Close in favor of #33