Fix IE7 and IE8 issues.

Summary: Resolves submit issues in IE7, scrollbars in IE7 and homepage layout issues in IE7 and IE8.

Test Plan: used IE7 and IE8. Logged in, bounced around. Checked Chrome as well.

Reviewers: epriestley, btrahan

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2469, T2470

Differential Revision: https://secure.phabricator.com/D4853