New topics redirecting incorrectly

[johnjamesjacoby]

After creating a new topic, you are redirected to the new topic's forum instead of the new topic itself.

This is a regression since 2.0.2.

[johnjamesjacoby]

(In [3912]) Redirects:

• Tweak topic and reply form fields to include redirect_to field.
• Fix redirect logic in single items after editing.
• Remove forum_id from new reply hidden fields, and calculate on handler based off of topic ID (to prevent mismatches.)
• Fixes #1829.

[johnjamesjacoby]

(In [3913]) Redirects:

• Remove redirect_to fields from edit form field functions, and trust handler logic to do its job.
• See #1829.