Some improvement. Windows example

Changes in \jdksmidi\driverwin32.h and jdksmidi_driverwin32.cpp
-now the driver retrieves the installed MIDI devices and keeps their
names in a static array
-introduced default values for semplifying calling: in particular, the
class MISequencerGUIEventNotifierWin32 can generate a safe Win32 message
number for communicating with the GUI
Changes in \jdksmidi\sequencer.h and jdksmidi_sequencer.cpp
-correct two bugs (see source)
Other minor changes.
Added the files examples\test_win32.h and test_win32.cpp, a working
Windows example using Win32 API. (See readme in this dir)