crowbar_batch: add support for crowbar batch export
crowbar_batch: use constants for alias expansion
crowbar_batch: add some TODO ideas for improvement
crowbar batch build: improve wait loop

It didn't correctly handle some states, e.g. when the proposal gets
queued.
barclamp_lib.rb: split up opt_parse into reusable chunks
barclamp_lib.rb: replace evil eval with call to lambda

AFAICS this feature supporting non-standard options is not currently
used by any script, so it should be safe to change.
crowbar_batch: add support for --include / --exclude