Improve collapsed style

Currently if a user was to collapse a table with a thead, the bottom
corners have no boarder radius, but the container does leaving it
looking out of place.
This commit adds the thead_collapsed class to the .thead (if present)
when collapsed or when set as collapsed from a cookie.
Fix #377 Installer suggests incorrect cookie domain

The logic for this was backwards. If `my_inet_pton($cookiedomain)` returns false, or `strpos($cookiedomain, '.')` returns anything but true, we have an invalid cookie domain.
Reply to own thread permission
Update index.php
Fixes the upgrade script (still referring to version 28 instead of 29)
Working on jQuery Conversion #251

Check All checkboxes work fine now.
Fixes ajax delete post in MyBB 1.8 #148
Working on jQuery Conversion #251

Fixed bunch of "onfocus" attributes on template calendar_addevent
Working on jQuery Conversion #251

Better use properties than attributes in this case
Working on jQuery Conversion #251

Mass Controls in Moderator Queue now working
fixes #484 - "Search for Users" in modcp
Fixes #411 Deleted user title remain
Fixing typo in get_ip() function
Merge pull request #371 from ATofighi/newlanguagelines

Add 'Mass Mail' language codes
use $mybb->get_input(...) instead of $mybb->input[...]
Merge pull request #475 from WildcardSearch/fix-336

Addressing #336
Merge pull request #504 from Stefan-ST/fix-346

Fixes #346 Calendar gmmktime() PHP warnings
Fixes #421 Moderators can't add announcements in modcp
Fixes #509 class_parser.php removes backlashes
Merge pull request #392 from ATofighi/fix-forumlink

Forums with threads cannot have forum link
Removes unnecessary space