remove parameterization of swing classes to compile with jdk6

As I described on the forum,

http://forum.soapui.org/viewtopic.php?f=1&t=22619&sid=a082ccb7a6cf2277f19297f20678a1b0,

compiling with jdk6 is no longer possible.

This pull request restores that by removing generics parameters in swing class usage.

If the intention was to completly drop jdk6 for compilation of soapui, please ignore this pull request.