miniobject: qdata array is not freed when the last qdata is removed
On GStreamer master, for GstMiniObjects that have had qdata, an array with room for 16 GstQDatas (total 256 bytes) is kept until the miniobject is freed, even if the last qdata has been removed earlier.
In our products, we can have 40000+ long-lived buffers that have qdata only very briefly. The GstQData arrays mean 10 MB on the heap, which is significant.
In GStreamer 1.14, the arrays were freed when the last qdata was removed. We suggest that behaviour is restored.