Image scaling, long word breaking and other small HTML/CSS changes

[Destroy666x]

Adds a CSS solution for this: http://community.mybb.com/thread-154473.html
It scales big images in: announcements, PMs, posts, signatures, events, profiles, help documents, poll options, previews, new reply thread review, etc. Long word breaking was introduced as well.

It also changes some minor CSS/HTML inconsistencies (css3 in wrong stylesheet, reorder other CSS, delete selectors without attributes, add .clear , .float_left and .float_right to some templates instead of inline CSS, etc.).

I tested it twice here: http://noo.hol.es/mybb18/ and didn't find any issues so I guess it can be merged before B2 - if someone finds mistakes they can be corrected.

[JordanMussi]

What about [code] and [php] MyCodes? Long lines of text force the container out much like an image...

[Destroy666x]

^

Long word breaking was introduced as well.

I just have to fix conflicts.

[Eldenroot]

good job! It must be tested properly

[Sama34]

@Destroy666x

[DiogoParrinha]

@Destroy666x

[Destroy666x]

Same as the other PR done today.

[JordanMussi]

PR was merged...