Show the interpolation mode in the status-bar. This is a little bit
more useful for people who are new to GNU Rocket than just using some
undocumented color-code in the track.
This is mostly just nit-pickery that allows most of the editor to
be compiled with MinGW. The nasty COM-stuff for the XML-loader in
syncdocument.cpp is still not compiling, though. There's also some
missing resource definitions, it seems.
