Quote beautifying

I do not like how the default quotes look like, so I made some changes on my 2.0 forum and finally decided to make a pull request for 2.1. Here how the quote will look after the changes (tested in FF, Pale Moon, Opera new and old, Chrome):
Post quote
![post_quote](https://cloud.githubusercontent.com/assets/6107569/4605808/21adcc1c-51fc-11e4-9f70-85a5b136bc8c.png)

PM quote
![pm_quote](https://cloud.githubusercontent.com/assets/6107569/4605809/21ef5d3a-51fc-11e4-9512-701e08602209.png)

Post quote on narrow window
![post_narrow_quote](https://cloud.githubusercontent.com/assets/6107569/4605810/22729308-51fc-11e4-9484-7136422cf149.png)

I know many people think the default theme should look simple and something like this would be better as mod. Usually I tend to agree with this, but I think quotes really need some beautifying.

My reasoning to remove the quotation mark:

1. After the changes it's much more obvious that the block is a quote, so I do not think they are needed anymore.
2. Not all languages use these opening quotation marks. For example in German and Bulgarian the opening quotation marks are these: "„". In Spanish, Russian and French are these: "«". 

Bulgarian - http://bg.wikipedia.org/wiki/%D0%9A%D0%B0%D0%B2%D0%B8%D1%87%D0%BA%D0%B8
French - http://fr.wikipedia.org/wiki/Guillemet
German - http://de.wikipedia.org/wiki/Anf%C3%BChrungszeichen
Russian - https://ru.wikipedia.org/wiki/%D0%9A%D0%B0%D0%B2%D1%8B%D1%87%D0%BA%D0%B8
Spanish - http://es.wikipedia.org/wiki/Comillas

I guess many more languages do not use "“" as opening quotation marks.
3. As image they looked good in all browsers, now every browser renders them more or less differently.

Signed-off-by: Hristo- <Hristo-@users.noreply.github.com>