gst: add wrapper for deinit function (#15)

* gst: add wrapper for deinit function

* build: prevent unused variable warning in cgo code compilation.

While compiling the code gcc complained with unused-variable
According to:
https://github.com/golang/go/issues/6883#issuecomment-383800123
Wall flag should not be used in CGO, nonetheless in this PR we only
remove the unused variable warning.

Co-authored-by: Solganik Alexander <alexanders@anyvision.co>

gst/gst_init.go

@@ -45,3 +45,10 @@ func Init(args *[]string) {
 	}
 	CAT = NewDebugCategory("GST_GO", DebugColorFgCyan, "GStreamer Go Bindings")
 }
+
+// Deinit is a wrapper for gst_deinit Clean up any resources created by GStreamer in gst_init().
+// It is normally not needed to call this function in a normal application as the resources will automatically be freed
+// when the program terminates. This function is therefore mostly used by testsuites and other memory profiling tools.
+func Deinit() {
+	C.gst_deinit()
+}

gst/pkg_config.go

@@ -2,7 +2,7 @@ package gst
 
 /*
 #cgo pkg-config: gstreamer-1.0
-#cgo CFLAGS: -Wno-deprecated-declarations -Wno-format-security -g -Wall
+#cgo CFLAGS: -Wno-deprecated-declarations -Wno-format-security -g -Wall -Wno-unused-variable
 #cgo LDFLAGS: -lm
 */
 import "C"