CRM-15377 fix - On changing price field option(s) from 'Change Fee Selection' doesn't update lineitem's label and unit_price

https://issues.civicrm.org/jira/browse/CRM-15377
Merge pull request #4237 from monishdeb/CRM-15377

CRM-15377 fix - On changing price field option(s) from 'Change Fee Selec...