Various utilities

* new utilities related to quaternion floating base parameterization / difference between qdot and v
* gradient output for various utility functions
* gradient utilities
* snuck in a code formatting fix for findKinematicPath

An all-Matlab pull request adding various utility functions that shouldn't change any of the current functionality. The only exception is a matGradMultMat fix when the input is an empty matrix.
i'm ok with either, but i do think we should be making these decisions and sticking to them.

i've pushed the code style guide to the wiki (instead of the pdf) and have been trying to update it:
https://github.com/RobotLocomotion/drake/wiki/Code-Style-Guide

On Aug 10, 2014, at 7:51 AM, Andres Valenzuela <notifications@github.com> wrote:

> In util/jointQdotTov.m:
> 
> > @@ -0,0 +1,46 @@
> > +function [Vq, dVq] = jointQdotTov(body, q_body)
> Not sure if we want to follow it here, but the MATLAB convention would be to use '2': jointQdot2v
> 
> —
> Reply to this email directly or view it on GitHub.
>