make marker popups work better

- Added overflow-auto and max height to popups
- Fixed overly broad and aggressive rule intended for tiles that was interfering with image styles in popups
- Made base type styles smaller

From:
![screen shot 2014-01-28 at 3 26 18 pm](https://f.cloud.github.com/assets/108094/2023321/9da8ac22-885a-11e3-8e26-d0e365849c5b.png)

To:
![screen shot 2014-01-28 at 3 26 02 pm](https://f.cloud.github.com/assets/108094/2023324/a28af236-885a-11e3-9e81-5c7ab49a931f.png)