Explicit hidden filed on topic creation(forum)

Users reported the confusing behaviour of "new topic" feature. This MR makes explicit the option that allows users to "leave comments" at the time they create a new topic instead of only the edition.

See travis-ci for test status for this branch.

@danielafeitosa @diguliu

Title changed from New topics now accepts reply by default to Explicit hidden filed on topic creation

Title changed from Explicit hidden filed on topic creation to Explicit hidden filed on topic creation(forum)

Status changed to merged

This behavior was super weird... :P

mentioned in commit 5e8e25e9

Milestone changed to 1.3

Reassigned to @diguliu

Reassigned to @diguliu