Summary: Fixes T7539. We need to set the "with-column" css class on the document body to make things like the jx-mask style-able. Also, make the global upload control only do it for the standard phabrcator page and not the document body.
Test Plan: dragged a file to conpherence column and it worked! uploaded a file to homepage with column open and it worked! uploaded a file to /file/ with column open and it worked!
Reviewers: chad, epriestley
Reviewed By: epriestley
Subscribers: Korvin, epriestley
Maniphest Tasks: T7539
Differential Revision: https://secure.phabricator.com/D12055