updates time scale handling

plugins/com.minres.scviewer.database/src/com/minres/scviewer/database/IWaveformDb.java

@@ -18,6 +18,11 @@ import java.util.List;
  */
 public interface IWaveformDb extends IHierNode {
 
+	/**
+	 * the time scale of the database. This is the exponent of the value i.e. -12 is ps
+	 */
+	public static final int databaseTimeScale = -15;
+	
 	/**
 	 * Gets the max time.
 	 *