Use uid as username when creating user with LDAP

Without that commit, each user created by a LDAP login would have the
first part of their email address as nickname.

This is not useful for LDAP, where a uid attribute is already set.
Let people know that Nihad Abbasov made a nice api wrapper.
Merge branch 'api-wrapper' into 'master'

Api wrapper
Merge branch 'use_ldap_uid_as_username_instead_of_first_part_of_email_address_on_user_creation' into 'master'

Use ldap uid as username instead of first part of email address on user creation
Merge branch 'master' of github.com:gitlabhq/gitlabhq
Merge branch 'master' of gitlab.com:gitlab-org/gitlab-ce