Fix info page style

When I click link "About your application's environment" at welcome page, the page style (such as font, background color etc) are broken. (see the following images.)

This cause is that the partial page loaded by xhr contains their own css.

So I stop containing css in loaded page.

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Before click:
![ 2013-01-04 15 51 05](https://f.cloud.github.com/assets/290782/42622/33f23390-563b-11e2-80c4-87c596d6f301.png)

After click:
![ 2013-01-04 15 51 17](https://f.cloud.github.com/assets/290782/42621/33c2d00a-563b-11e2-9ae6-f24e4ae31590.png)