Fix for ZF-1052:  Modified the code to detect invalid usernames, and send back an HTTP 401 instead of 400. This gives the user another chance to enter a username.
Fix for ZF-1052:  Modified the code to detect invalid usernames, and send back an HTTP 401 instead of 400. This gives the user another chance to enter a username.

git-svn-id: b6e219894c353fb1d215c78b2075057d8daadfba@3957 44c647ce-9c0f-0410-b52a-842ac1e357ba

svn2github/zend_framework,jupeter/zf1,jupeter/zf1,svn2github/zend_framework,svn2github/zend_framework,jupeter/zf1,tjohns/zf,svn2github/zend_framework,tjohns/zf,tjohns/zf,svn2github/zend_framework