Some new properties to custom each pixels

I've added some properties to give us a little more power around the inner stroke and the top edge of the tab bar.

Here is some images to illustrate before/after each commit

Before adding the inner stroke property
![before-1](https://f.cloud.github.com/assets/328718/155257/2bc2f676-7640-11e2-8d3b-0da8011f75b2.png)
After, with a inner stroke color set to clearColor
![after-1](https://f.cloud.github.com/assets/328718/155262/3ffef66c-7640-11e2-97f8-4538b47bacbd.png)

Before adding the top edge property
![before-2](https://f.cloud.github.com/assets/328718/155265/4ae5b9c6-7640-11e2-81c0-290d79794a42.png)
After
![after-2](https://f.cloud.github.com/assets/328718/155267/4e38640c-7640-11e2-9d0d-0470f97547ae.png)