Submitted by Julien Isorce @cap

Link to original bug (#740108)

Description

Examples:

• gst-launch ... ! avdec_ + tab should suggest the available avdec decoders.
• gst-launch filesrc location=sample + tab should suggest available local files starting with "sample" in current directory. (was working on 0.10)
• gst-inspect matroskad + tab should complete to matroskademux.

It seems it was supported in the past but not maintained or ported at some point. If someone could point those old commits if exist, that would be great.