lower opacity of landuse=residential


This is a must fix before we encourage people to use the master zip in github.

Right now, the master on github looks like the following: 
![selection_027](https://f.cloud.github.com/assets/955351/981326/34b79d8e-075b-11e3-9194-d3a84b50c57c.png)


I lowered the opacity of the landuse=residential in this pull request and this is how it looks: 
![selection_026](https://f.cloud.github.com/assets/955351/981340/fb98aa50-075c-11e3-9a25-9c308d508e7e.png)


This problem does not happen in the ubuntuone zip which looks like: 
![selection_028](https://f.cloud.github.com/assets/955351/981356/2e1aab0e-075d-11e3-8ddb-a03fa7904d9b.png)



This bug was likely introduced when I changed the color of the landuse=residential to be different from the building=yes color (if you want me to, I can bisect it to see exactly where this bug started).