Fixed few coverity issues
Fixed few coverity reported issues around concurrency, null checks
Fixed few coverity issues reported
    Fixed CLOUDSTACK-7303 [LDAP] while importing ldap users, update the user info if it already exists in cloudstack
CLOUDSTACK-7283: listUsers - for regular user, only return the caller info. If there are more users under the same account, their information should never be returned
CLOUDSTACK-7295: VMs is Stopped state have no host ID, resulting in NPE
CLOUDSTACK-7312:ISOs cannot be downloaded from URLs without matching
file extensions.
CLOUDSTACK: Test script to verify fix for CS-5332

Signed-off-by: sanjeev <sanjeev@apache.org>
Signed-off-by: Santhosh Edukulla <santhosh.edukulla@gmail.com>
CLOUDSTACK-7083: Add SAML2 SSO plugin skeleton and stub

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
client: add saml2 plugin dependency on client artifact

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
saml2: add spring security saml2 extension 1.0.0.RELEASE

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
ApiConstants: add Api constant registered

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
ApiErrorCode: Add API error code 401, 405

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
commands.properties: add login,logout,samlsso,samlslo apis

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
saml2: add opensaml as dependency

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
APIAuthenticator: Add interface definition for the auth mechanisms

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
APIAuthenticationType: Add auth enum type, login or logout

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
APIAuthenticationManager: Add Auth manager definition

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
DefaultLogoutAPIAuthenticatorCmd: Refactor and implement the logout mechanism

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
DefaultLoginAPIAuthenticatorCmd: Refactor and implement the default login mechanism

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>