[seiscomp, scanloc] Install, add .gitignore

etc/descriptions/seedlink_mk6.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<seiscomp>
+	<binding module="seedlink" name="mk6" category="sources">
+		<description>MK6</description>
+		<configuration>
+			<parameter name="proc" type="string">
+				<description>
+				Name of the proc object (defined in streams.xml); used for processing
+				raw streams (streams submitted by a plugin as raw samples).
+				</description>
+			</parameter>
+		</configuration>
+	</binding>
+</seiscomp>