adding error constants and prompt constatnts

git-svn-id: https://svn.wso2.org/repos/wso2/carbon/platform/trunk@178205 a5903396-d722-0410-b921-86c7d4935375
moving consent pages to endpoint

git-svn-id: https://svn.wso2.org/repos/wso2/carbon/platform/trunk@178206 a5903396-d722-0410-b921-86c7d4935375
implementing consent store

git-svn-id: https://svn.wso2.org/repos/wso2/carbon/platform/trunk@178207 a5903396-d722-0410-b921-86c7d4935375