Fixed some display issues (class css bg, small tablet layout, and phone class bg image and padding)

@wescott  

added "target-densitydpi=device-dpi" meta tag on base.html to fix nexus and other android device scaling issues

Before Image on Nexus 7:
![2013-01-28_09 46 21_ASUS NEXUS 7](https://f.cloud.github.com/assets/3364609/104220/85e83736-697c-11e2-819d-0ca4f1b38cae.png)

After Image on Nexus 7:
![2013-01-28_09 47 30_ASUS NEXUS 7](https://f.cloud.github.com/assets/3364609/104223/96388064-697c-11e2-8a45-bf5437430901.png)

added .databases to responsive.css in order to fix bg-image display issues

Before image on iPhone:
![2013-01-28_10 55 40_Giulio Gratta s iPhone](https://f.cloud.github.com/assets/3364609/104249/f0a0970c-697d-11e2-826b-de7414db87a4.png)

After image on iPhone:
![2013-01-28_11 06 10_Giulio Gratta s iPhone](https://f.cloud.github.com/assets/3364609/104252/fe1c07d6-697d-11e2-95f7-619f025ed016.png)

added CSS for white background on body.css to homogenize class look on home page

Before image on laptop:
![Screen Shot 2013-01-28 at 11 09 17 AM](https://f.cloud.github.com/assets/3364609/104259/60c58a56-697e-11e2-8429-93773819a246.png)

After image on laptop:
![Screen Shot 2013-01-28 at 11 09 44 AM](https://f.cloud.github.com/assets/3364609/104260/6eecc45a-697e-11e2-8c15-9b5703c07b05.png)