Merge pull request #1 from a-price/master

Fixing compile on Ubuntu.
Added analytical leg IK.
Breaking it in
Please rescue me from pointer hell
Even this fails
Pointer hell escaped!
Playing with pointers and copy constructors
Now we're getting somewhere
Stable and safe
Able to read URDF -- now needs to parse
Updated a few details
Parsing URDFs!
Accepts non-z joint axes
A little cleanup
A little more cleaning
Validated Jacobians -- Nothing special
Replacing pointer returns with reference returns
Deleted some deprecated code
Fixed iterator usage
Starting a DLS solver