Clean up some text around parallel requests (#193)
Clean up some text around parallel requests (#193)

Really this section shouldn't be just about asyc stuff, but instead
dealing with more than one request at a time.

Signed-off-by: Doug Davis <ff3bde741799c0eff815b83a54eda3fc494df54f@us.ibm.com>
servicebroker/servicebroker,duglin/servicebroker,servicebroker/servicebroker,servicebroker/servicebroker,openservicebrokerapi/servicebroker