Generic _media_update() func., added func. to update status with a photo.
Generic _media_update() func., added func. to update status with a photo.

* Generic _media_update() func. for the 3 media api calls

* Added func. to update status with a photo. updateStatusWithMedia()

Oire/twython,vivek8943/twython,akarambir/twython,mgrouchy/twython,Fueled/twython,joebos/twython,Hasimir/twython,ryanmcgrath/twython,Devyani-Divs/twython,ping/twython,fibears/twython