Ignore case for DIDLLite and LastChange parsing

"Be tolerant in what you accept". Especially the correct casing of
Metadata seems problematic, causing issues in parsing LastChange from
various renderers.

https://bugzilla.gnome.org/show_bug.cgi?id=678784
Fix get_{create|search}_classes

We need to return the content of the first child (a TEXT node) and not
the content of the node itself.

Fixes:
    https://bugzilla.gnome.org/show_bug.cgi?id=676372
Fixed a potential memory corruption error in parse_additional_inf.

This occurs in the "DLNA.ORG_FLAGS=" portion of the protocol info
is < 8 bytes.

https://bugzilla.gnome.org/show_bug.cgi?id=674322
Prepare 0.10.3
Update license headers
Post-release version bump
Add XML helper functions getting number from child contents.

Will be needed by update ID getters in object and container.
Add XML helper function removing child element.

Will be needed for unsetting independent properties.
Add objectUpdateID to GUPnPDIDLLiteObject.

Will be needed for Tracking Changes Option of ContentDirectory.
Add updateCount to GUPnPDIDLLiteResource.

Will be needed for Tracking Changes Option of ContentDirectory.
Add private getter of GUPnPXMLDoc from object.

Will be needed by container for setting child elements.
Add containerUpdateID to GUPnPDIDLLiteContainer.

Will be needed for Tracking Changes Option of ContentDirectory.
Add totalDeletedChildCount to GUPnPDIDLLiteContainer.

Will be needed for Tracking Changes Option of ContentDirectory.
Some small doc fixes.
Allow 'upnp:createClass' attributes retrieval

Existing gupnp_didl_lite_container_get_create_classes (...)) API doesn't
allow to retrieve the "IncludeDerived" and friendlyName attributes of the
"upnp:createClass" elements, the returned result is a Glist of UTF8 string
 representing the class name.

To enable the retrieval of these attributes, this change adds:

- A new GUPnPDIDLLiteCreateClasses GObject with the "upnp:createClass"
 properties (content, includeDerived, friendly name) and their related
 Getter/Setter APIs.

- A new GUPnPDIDLLiteContainer GObject method to get all its
"upnp:createClass" elements as a GList of GUPnPDIDLLiteCreateClasses
 objects:

GList * gupnp_didl_lite_container_get_create_classes_full(
					GUPnPDIDLLiteContainer *container);

https://bugzilla.gnome.org/show_bug.cgi?id=684297
Guard deprecated function
Make Requires private in pkg-config files

Putting stuff in Requires means applications using
this library will link against that when it might
not be needed at all because they use none of that
libraries symbols directly.

If only the cflags is needed (because public headers
includes headers from that package) they
can be private to avoid uselessly linking.

See #2 in http://people.freedesktop.org/~dbn/pkg-config-guide.html#faq

https://bugzilla.gnome.org/show_bug.cgi?id=685477
Link to gobject-2.0 and libxml-2.0 as well

These where previously pulled in by underlying libraries
which leaked these dependencies. It happens to be that gupnp-av
needs these too and should not rely on anything else pulling it in.

(For static linking to work, these should probably be added to
the pkg-config files Requires.private field as well.)

https://bugzilla.gnome.org/show_bug.cgi?id=685477
Generate vapi from GIR data
Bump GUPnP requirement