Adhere to REP 103 URDF conventions

[jjaime2]

Currently, several of the STLs in our URDF follow no particular convention which makes modifying our URDF more of a hassle than it needs to be. Each component of our system should abide by the REP 103 convention, which will reduce integration issues. In particular, we have observed that small inconsistencies in our kinematic structure defined by URDF have caused large enough errors at our tool tip to result in bite acquisition failures.

Below is the hand of our Jaco arm, there are two frames that would be excellent as parent frames, j2n6s200_link_6 below and j2n6s200_end_effector above

Below are several examples of components that can be refactored to follow this convention:

enclosureTop:

forkHandle:

forkHandleCover:

forkTine:

forque:

FT:

FTMount: