Move whereas clauses to preamble

[cmbirk]

It looks like the US House is using the preamble for these sections:

http://www.gpo.gov/fdsys/bulkdata/BILLS/114/1/hres/BILLS-114hres400ih.xml

[cmbirk]

I'm not sure where I can find the list of available concrete elements. The whereas element in that resolution is nowhere to be found in the User Guide, and there is also no main element as described in the guide either...

[cmbirk]

I've created one example of the move in 31e2880