add shebang lines to all lib files

With gerrit 2.8, and the new change screen, this will trigger syntax
highlighting in gerrit. Thus making reviewing code a lot nicer.

Change-Id: Id238748417ffab53e02d59413dba66f61e724383
diff --git a/lib/config b/lib/config
index a4d0328..c0756bf 100644
--- a/lib/config
+++ b/lib/config
@@ -1,3 +1,5 @@
+#!/bin/bash
+#
 # lib/config - Configuration file manipulation functions
 
 # These functions have no external dependencies and the following side-effects: