Support multiple export formats and export from entity view

#134 
#129 

Multiple formats on Biblio view:
![export3](https://f.cloud.github.com/assets/99186/1849097/b112d5d6-76a7-11e3-86ec-7d04ac807f63.png)
![export2](https://f.cloud.github.com/assets/99186/1849098/b367fb54-76a7-11e3-8d58-439f5c49720d.png)
Multiple formats on entity view:
![export1](https://f.cloud.github.com/assets/99186/1849099/b52caca0-76a7-11e3-8cf8-2b430a9c186c.png)