gst/goom/: Free a bunch of stuff, and initialise things to fix leaks and valgrind...

gst/goom/: Free a bunch of stuff, and initialise things to fix leaks and valgrind warnings in the testsuite.

Original commit message from CVS:
* gst/goom/config_param.c: (goom_plugin_parameters_free):
* gst/goom/convolve_fx.c: (convolve_init), (convolve_free):
* gst/goom/filters.c: (zoomFilterVisualFXWrapper_free):
* gst/goom/flying_stars_fx.c: (fs_free):
* gst/goom/goom_config_param.h:
* gst/goom/goom_core.c: (goom_init), (goom_close):
* gst/goom/goom_plugin_info.h:
* gst/goom/gstgoom.c: (gst_goom_finalize):
* gst/goom/lines.c: (goom_lines_free):
* gst/goom/plugin_info.c: (plugin_info_init), (plugin_info_free):
* gst/goom/surf3d.c: (grid3d_free):
* gst/goom/surf3d.h:
* gst/goom/tentacle3d.c: (tentacle_free):
Free a bunch of stuff, and initialise things to fix leaks
and valgrind warnings in the testsuite.
Fixes: #529268