fs: Add --dump flag, introduce --dump requests, responses and remove --dump-auth, --dump-filters

Now --dump-flag is written as --dump flag. This is a comma separated list which can contain

  * headers - HTTP headers as before
  * bodies  - HTTP bodies as before
  * requests - HTTP request bodies
  * responses - HTTP response bodies
  * auth - HTTP auth
  * filters - Filter rexeps

Leave --dump-headers and --dump-bodies for the time being but remove
the other --dump-* flags as they aren't used very often.

fstest/fstest.go

@@ -59,8 +59,12 @@ func Initialise() {
 	if *Verbose {
 		fs.Config.LogLevel = fs.LogLevelDebug
 	}
-	fs.Config.DumpHeaders = *DumpHeaders
-	fs.Config.DumpBodies = *DumpBodies
+	if *DumpHeaders {
+		fs.Config.Dump |= fs.DumpHeaders
+	}
+	if *DumpBodies {
+		fs.Config.Dump |= fs.DumpBodies
+	}
 	fs.Config.LowLevelRetries = *LowLevelRetries
 	fs.Config.UseListR = *UseListR
 }