libgimpwidgets: add new widget GimpColorProfileView

which is a totally trivial GtkTextView subclass and displays
color profile information.
libgimpwidgets: use a GimpColorProfileView in GimpColorProfileChooserDialog
libgimpcolor: move the GimpColorProfile typedef to gimpcolortypes.h
libgimpwidgets: #include gimpimageprofileview.h from gimpwidgets.h
app: use a GimpColorProfileView in GimpImageProfileView

and parse the profile in gimpimageprofileview.c instead of calling the
lcms plug-in. Make the app link against lcms. This is WIP because the
widget is of course the wrong place for such profile parsing code.