Always show inline comment column in Pholio
Summary:
- Always show the column so there's no jumping around when comments are added.
- Set width to 320px so we can mobile it (not 100% sure how this will work yet).
- When there are too many comments, scroll them internally.
Test Plan: {F33552}
Reviewers: ljalonen, chad
Reviewed By: chad
CC: aran
Differential Revision: https://secure.phabricator.com/D5071