Fix writing orientation and date exif tags in camerabin.

Orientation tags need to be transformed from the string tag returned
by gstreamer to the orientation in degrees.  Date tags need to be
inserted with gst_date_time_new_local_time.  Finally setting a tag
value shouldn't clear all other tags.

Change-Id: I28922148251084c12cf6c93d9b097fa5df41da9d
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>
Fix gstreamer crash when meta-data is of incorrect type.

GStreamer tags are typed and the correct type must be used when inserting
a value into a GstTagList or subsequent merges or data accesses can crash
because of invalid casts.

Found while adding additional mappings for GPS values.

Change-Id: I95ab40a480a4685bf4e69064315557faa9de288e
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>
Add meta-data mappings for GPS and camera make and model to camerabin.

This enables writing gps positioning information to captured images.

Change-Id: I663f7b94b5e6040865358df1ae45d67b73c54f92
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>
GStreamer: Remove tags when an invalid QVariant is assigned.

Clear the tag list before syncing with reference set so old values
are removed and explicitly remove invalid QVariants from the reference
set so that the type correction doesn't result in invalid values
being written instead.

Change-Id: I7d1bdc95cd2a2d601720db84c9b3ef629477bc99
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>
Restore the size of the focus rect to 1/3 viewfinder.
Merge pull request #22 from adenexter/gps

Add meta-data mappings for GPS tags as well as camera make and model.