CSS/HTML consistency, image scaling and word breaking

Implements image scaling, word breaking and fixes several CSS/HTML
inconsistencies
Fixes #938 - Get more Smiles box bug
fix: error message showthread.php?pid=x for deleted posts, refs #947

* showthread.php
  * added check if post with set pid exists before a thread with tid null is searched in the db
Merge pull request #950 from Nik101010/fix-947-feature

fix: error message showthread.php?pid=x for deleted posts, refs #947
Fixes #946 Instant PM notification not saved for Thread Subscription Mode

#946
Merge pull request #959 from PirataNervo/featurefix-946

Fixes #946 Instant PM notification not saved for Thread Subscription Mode
Fixes #944 buddylist popup not opening
Merge pull request #960 from PirataNervo/featurefix-944

Fixes #944 buddylist popup not opening
Committing changes from #673 to feature
Merge pull request #939 from ATofighi/patch-3

Fixes #938 - Get more Smiles box bug
Implements #905 Add class to smilies
Implements #857 Jump to Page in pagination
Adds AJAX to Security questions #894
Implements #430 Moderation Notifications
Intruducing https://github.com/mybb/mybb/issues/197

Warnings when users try to change settings which often cause problems.
Also a JS password comparison.
Merge pull request #963 from Destroy666x/instsett

Introducing https://github.com/mybb/mybb/issues/197
Feature #439 & #430
Feature #439 Moderate Groups
Please work...

Thanks.
Moved img SCEditor scaling to every theme...

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