Make some strings in `ArcanistPhutilXHPASTLinter` translatable

Summary: `pht`ize some string in `ArcanistPhutilXHPASTLinter` so that they are translatable.

Test Plan: Not 100% sure that I am doing it right...

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D10431
Add some missing function parameter typehints

Summary: Add some missing function parameter typehints to the `ArcanistPhutilXHPASTLinter` class.

Test Plan: Eyeball it.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D10430
Patch: don't complain about reviewers not being specified.
This will break in the future when upstream arc incorporates T4631. Hopefully there will be a better solution by then
if you didn't specify a reviewer, suggest projects