Don't require scollback to edit scrollback lines

text_max_lines also affects how many lines you can view not just scrollback
Point to new download url
Update installer to point to news
change URL for "Contents" option in "Help" menu

I propose that the address for the help contents is changed to docs.hexchat.org over simply being hexchat.org.
Merge pull request #398 from thor/patch-1

change URL for "Contents" option in "Help" menu
fix tray menu placement issues

notably top taskbar issues on windows
Add autojoin back
Merge remote-tracking branch 'upstream/master' into 2.9.5