Add more supported entities to the Batch envelope.
Merge branch 'master' of github.com:ruckus/quickbooks-ruby

Conflicts:
	lib/quickbooks/model/batch_request.rb
Allow a couple percent fields to be optional. Add TxnTaxDetail node to a sales receipt so we can send tax info.
Merge branch 'master' of github.com:elevation/quickbooks-ruby
Merge remote-tracking branch 'upstream/master'