R1:0250b48c0557

Add login buttons for button logins, fix LDAP form

Summary: Ref T1536.

Test Plan:
{F46555}

{F46556}

Reviewers: chad, btrahan

Reviewed By: chad

CC: aran

Maniphest Tasks: T1536

Differential Revision: https://secure.phabricator.com/D6209