[2016.09.15] srLib Valkyrie model assembly

DONE

1. Successfully reading URDF files and get data
   
   
   
2. mapping (joints' and links' index) -----> (joints' and links' parameters)
   
   
3. Automatically assemble
   
   

TODO

1. need to make some of rotation joint axis
2. need to add 5 more parts(hazard camera parts) <-- URDF reader debugging needed