gst/sine/demo-dparams.c: Use double dparams, not float.

gst/sine/demo-dparams.c: Use double dparams, not float.

Original commit message from CVS:
* gst/sine/demo-dparams.c: (quit_live),
(dynparm_log_value_changed), (dynparm_value_changed), (main):
Use double dparams, not float.
* gst/sine/gstsinesrc.c: (gst_sinesrc_class_init),
(gst_sinesrc_init): Change sync default to FALSE, since multiple
sync'd elements don't really work correctly.
* gst/volume/gstvolume.c: (volume_class_init), (volume_init),
(volume_update_volume), (volume_get_property):  Change dparam
to double.