Fix accordion section issues, add tests

Closes #291 

Fixed all rebase issues. Will delete earlier PR (`accordion-sections` branch) when this gets approved. 

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![image](https://cloud.githubusercontent.com/assets/302258/3405732/457fb7c4-fd81-11e3-9814-9f11d3251372.png)

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![image](https://cloud.githubusercontent.com/assets/302258/3405741/80df5dce-fd81-11e3-8d24-1b12f493252b.png)

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![image](https://cloud.githubusercontent.com/assets/302258/3405744/8fac772e-fd81-11e3-89ac-9feaa21752f8.png)