title: Default settings for http inbound gateway header mapping
body: <p>I have an application which has many int-http inbound-gateways. I now have a requirement to  map a non-standard header from an http request. I know I can use <code>mapped-request-headers</code> to select which headers to be mapped, which is what I'm currently doing.</p>
  
  <p>The problem is, dealing with all these gateways, I'll need to update each one to use the correct mappings. And furthermore the header should change (coming from a 3rd party), I would need to update ALL the gateways.</p>
  
  <p>Is there a global setting for the inbound gateways where I can set the default mappings? This way I'd only need to change one setting and all the gateways would be updated.</p>
  
  <p>A possible solution would be to implement <code>DefaultHttpHeaderMapper</code>, but is there an alternative (easier) method?</p>