player: Only emit some signals via the main context if the target state is >= PAUSED
player: Only emit some signals via the main context if the target state is >= PAUSED

Also make sure that the GstPlayer instance stays valid all the time when doing
async notifications or calls.

amorenoc/gst-player,justinjoy/gst-player,codomania/gst-player,jabiers/gst-player,jabiers/gst-player,sdroege/gst-player,justinjoy/gst-player,guiseco/gst-player,guiseco/gst-player,amorenoc/gst-player,JimmyOhn/gst-player,codomania/gst-player,shakin/gst-player,shakin/gst-player,sdroege/gst-player,JimmyOhn/gst-player,jabiers/gst-player,justinjoy/gst-player,JimmyOhn/gst-player,guiseco/gst-player,sdroege/gst-player,codomania/gst-player,shakin/gst-player,amorenoc/gst-player,JimmyOhn/gst-player,JimmyOhn/gst-player,amorenoc/gst-player,codomania/gst-player,sdroege/gst-player,amorenoc/gst-player,codomania/gst-player,sdroege/gst-player