_T() macro won't build on Solaris

Hello,

I've done a package of pgadmin3 1.16.1 for Solaris 10, built using
Solaris Studio against wxWidget 2.8.12.
I had some issues because of  the use of the _T() macro in several
places: that conflicts with  another one on that platform.

After replacing it everywhere with wxT() (see patch below), it built fine.
Since that macro is being discouraged by the wxWidget project, I think
it should be the right way?

I hope that can help!

Thanks,

Laurent