Allow exceptions to be handled outside wsmeext.pecan
Created originally on Bitbucket by jianingy (Jianing Yang)
Changesets for this Pull Request have not been imported, because it had been already declined on Bitbucket. Marked as closed by the import user.
Currently, all exceptions are catched by wsmeext.pecan. This commit add an argument to expose' named
expect_exception' to allow middlewares outside wsmeext.pecan handle exceptions.