[units] Do not be locale-dependant on string conversion
[units] Do not be locale-dependant on string conversion

When dumping a ClutterUnits structure to a string we are using a bare
g_strdup_printf(), which unfortunately is locale dependant. So, for
instance, a type of CLUTTER_UNIT_EM and a value of 42 are stringified
as:

        C:      42.00 em
        en_GB   42.00 em
        it_IT   42,00 em
        fr_FR   42,00 em

This would not be a problem -- clutter_units_from_string() allows both
'.' and ',' as fractionary part delimiters. The test suite, on the
other hand, does not know that, and it checks for exact matches with
the C locale.

Calling setlocale(LC_ALL,"C") at the beginning of the conformance test
suite is not a good idea, because it would prevent external testing; and
it's a lame cop out from doing exactly what we have to do -- pick a format
and stick with it.

Like other platforms, languages and frameworks before us, we opt to
be less liberal in what we create; so, we choose to always stringify
ClutterUnits with fractionary parts using '.' as the delimiter.

Fixes bug:

  http://bugzilla.openedhand.com/show_bug.cgi?id=1763

djdeath/clutter-multithreaded,Distrotech/clutter,GNOME/clutter,GNOME/clutter,djdeath/clutter-multithreaded,djdeath/clutter-android,ebassi/clutter,spatulasnout/clutter,Distrotech/clutter,Distrotech/clutter,collects/clutter,Distrotech/clutter,djdeath/clutter,nobled/clutter,djdeath/clutter,collects/clutter,nobled/clutter,spatulasnout/clutter,heysion/clutter-clone,djdeath/clutter-multithreaded,jigpu/clutter,heysion/clutter-clone,collects/clutter,spatulasnout/clutter,jigpu/clutter,ebassi/clutter,heysion/clutter-clone,djdeath/clutter-android,djdeath/clutter-android,nobled/clutter,jigpu/clutter,collects/clutter,rkudiyarov/clutter_osx,kerrickstaley/clutter-vala,djdeath/clutter,ebassi/clutter,djdeath/clutter-multithreaded,djdeath/clutter-android,GNOME/clutter,djdeath/clutter,djdeath/clutter-android,rkudiyarov/clutter_osx,djdeath/clutter,rkudiyarov/clutter_osx,ebassi/clutter,heysion/clutter-clone,heysion/clutter-clone,jigpu/clutter,ebassi/clutter,kerrickstaley/clutter-vala,Distrotech/clutter,GNOME/clutter,kerrickstaley/clutter-vala,Distrotech/clutter,dlespiau/clutter,dlespiau/clutter,kerrickstaley/clutter-vala,jigpu/clutter,spatulasnout/clutter,dlespiau/clutter,GNOME/clutter,jigpu/clutter,spatulasnout/clutter,djdeath/clutter,collects/clutter,rkudiyarov/clutter_osx