Minor phutil_tag/HTML fixes
Summary:
- In stack traces, a , should clearly be a ..
- In Calendar, a 'td' got swapped with a 'p' somewhere.
- In old-style transaction views, strlen() is no longer a sufficient test.
Test Plan:
- Verified stack traces render correctly.
- Verified calendar renders correctly.
- Verified Maniphest transactions with no comment no longer have a little empty div a few pixels high.
Reviewers: chad
Reviewed By: chad
CC: aran
Differential Revision: https://secure.phabricator.com/D4971