Because of a history of cut and paste, the different enumeration
and marshal generation generation shell snippets were using the
same temporary file names. This caused problems for parallel
builds.
http://bugzilla.gnome.org/show_bug.cgi?id=591474
When AM_SILENT_RULES is available, use it to strip down the output
of make so we can see what's important rather than gigantic long
compile lines.
Use 'make V=1' to see everything again.
Fix a couple of places where we had 'cmp' rather than 'cmp' and were
getting standard-error spew about missing files when generating
enum-types.h files.
http://bugzilla.gnome.org/show_bug.cgi?id=591002
