rtl::O[U]String::operator== -> to rtl::O[U]String::equals

poking at some performance stuff, I was surprised by some sluggish
comparisons of rtl::O[U]Strings where I knew that each string was a
shallow copy of the same underlying rtl_uString. Turns out that equals()
does the "shares same rtl_uString" optimization, but operator== doesn't.

I can't thing of a good reason why that might be ?, so now converted
operator== to simply call equals 
http://cgit.freedesktop.org/libreoffice/core/commit/?id=2b168feccee9c367152e106386101be903e4f1db
which makes my example zoom along like I had originally expected it to.

C.