This allows native CloudStack users to change password in UI when LDAP
is enabled. Overall changes:
- A new usersource returned in the listUsers response
- Removed ldap check in the UI, replaced with check based on user source
- DB changes to include user.source in user_view
- Changed UI error message for non-native users trying to change password
Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>