Fix "Library name" and "Library type" in cmake output

[rrrapha]

Before:

...
-- PortMidi Library name:
-- Build type: Release
-- Library Type:
...

After:

...
-- PortMidi Library name: portmidi
-- Build type: Release
-- Build shared library: ON
...

[rbdannenberg]

Thanks. Sorry for the delay. I'll pull the request. Looks good to me.