Gst::Pipeline: wrapped missing enums, added simple test

	* gstreamer/src/pipeline.hg: wrapped PipelineFlags enum
	* tests/Makefile.am:
	* tests/test-pipeline.cc: added very simple test
	* .gitignore: added pipeline output file to ignored list
Gst::Object: implemented easy accecss to an object's refcount.

Sometimes (especially, in tests) we need to check refcount of an object.
This change gives developer simple access to a refcount number.
User had to use 'GST_OBJECT_REFCOUNT(GST_OBJECT(obj->gobj()))' to get a
refcount. Now it is much easier, just use 'obj->get_refcount()'.

	* gstreamer/src/object.[ccg|hg]: added get_refcount method to an
	Gst::Object class.