If the modem is started with --log-level=DEBUG, they will not be shown.

The MMManager object now derives from the gdbus-codegen-generated
MmGdbusOrgFreedesktopModemManager1Skeleton object, and implements the handlers
for the SetLogging() and ScanDevices() DBus methods.

The main program is also modified to be based on GDBus.

Make it more flexible, add logging to a file, and absolute and
relative timestamps.

More info:
https://bugzilla.redhat.com/show_bug.cgi?id=585394
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-1172

dbus-glib was not properly enforcing the 'access' permissions on
object properties exported using its API.  There were 2 specific bugs:

1) dbus-glib did not enforce the introspection read/write property
permissions, so if the GObject property definition allowed write
access (which is sometimes desirable), D-Bus clients could modify
that value even if the introspection said it was read-only

2) dbus-glib was not filtering out GObject properties that were
not listed in the introspection XML.  Thus, if the GObject defined
more properties than were listed in the introspection XML (which is
also often useful, and MM uses this quite a bit) those properties
would also be exposed to D-Bus clients.

To fix this completely, you need to:

1) get dbus-glib master when the patch is commited, OR grab the
patch from https://bugzilla.redhat.com/show_bug.cgi?id=585394 and
build a new dbus-glib

2) rebuild ModemManager against the new dbus-glib

Distributions should set dist-version at build time with the
package version and revision, so for RPM-based distros you'd

--with-dist-version=%{version}-%{release}

which will be printed out on MM startup to help debugging.