Avoid deleting whole threads when ripping 1 page

[roelderickx]

Hi,

While ripping a thread with more than 20 posts I found only the last messages are saved in the database.

The script downloads averything and the output confirms this, but in below example only the 5 messages with sequences 20 to 24 will be saved in the database:

Gathering data from https://www.tapatalk.com/groups/***/viewtopic.php
looking for thread t=1827&start=0 - downloaded - ***
10 saved
looking for thread t=1827&start=20 - downloaded - ***
5 saved

Reason is the download_thread function which is called recursively and deletes the whole thread every time, I modified it to delete only the posts from $start to $start + $posts_per_page - 1

[roelderickx]

After using the script for a while, it turns out there is more to be done before it works:

• The login has been changed
• A page contains only 10 posts in stead of 20
• The parsing of the username has been changed
• Bogus and unauthorized threads must be detected differently
• Fetching the edit count always returns 403 forbidden
• Some dates cannot be parsed if they are in the current year, eg '11:41 PM - Apr 03'

I resolved all issues above except the last two, I don't consider it to be that important. Do you want me to include all changes I made in this pull request?