added manpage for gst-launch-ext, now thomas must add it to the build :)

Original commit message from CVS:
added manpage for gst-launch-ext, now thomas must add it to the build :)

tools/gst-launch-ext.1

+.TH "GStreamer" "1" "February 2002" "" ""
+.SH "NAME"
+gst\-launch\-ext \- Run a predefined GStreamer pipeline
+.SH "SYNOPSIS"
+\fBgst\-launch\-ext\fR \fI[OPTION...]\fR PIPELINE\-DESCRIPTION
+.SH "DESCRIPTION"
+.LP 
+\fIgst\-launch\-ext\fP is a tool that is used to run a basic predefined \fIGStreamer\fP pipeline.
+
+All supported formats in GStreamer should be playable by simply typing:
+
+ gst\-launch\-ext filename
+
+
+.SH "SEE ALSO"
+.BR gst\-guilaunch (1),
+.BR gst\-complete (1),
+.BR gst\-register (1),
+.BR gst\-inspect (1),
+.BR gst\-launch (1),
+.SH "AUTHOR"
+The GStreamer team at http://gstreamer.net/