What is the view of Islam about [transgender][1]/[bigender][2] people?

Are they considered Muslims?

> anyone who pronounces the shahada a Muslim

My questions are:

- Some rules in Islam (like wearing gold, hijab) are different between males and females. What should those people do?

- What does Islam say about their marriage? 


  [1]: https://en.wikipedia.org/wiki/Transgender
  [2]: https://en.wikipedia.org/wiki/Bigender