force torque working commit.
contactSensorTest now passes.
resolve default argument redefinition compiler errors.  fixes #290.
Merge pull request #293 from patmarion/drakeGradientUtil-fixup

resolve default argument redefinition compiler errors.  fixes #290.
Merge pull request #287 from mposa/master

ContactForceTorqueSensor update
move contact force sensors back out of dev
resolves multi-frame indexing bug #291
Adds minimum version arg when finding octomap

Also updates the cmake submodule to get the two-argument form of the
pods_find_pkg_config macro.
Merge pull request #297 from avalenzu/octomap-version

Adds minimum version arg when finding octomap
Merge pull request #294 from RussTedrake/multiframe

fixes multi-frame frame_id logic bug
Add drakeFunction package and basic classes.

Defines the following functions
  * Affine transformations
  * Constant elementwise powers
and the following ways of combining them
  * Composition
  * Concatenation
Add drakeFunction.Sum as a drakeFunction.Container
Reimplement Sum as a regular drakeFunction.

This leaves us with only two drakeFunction.Container classes:
  * Composed
  * Concatenated
which strikes me as cleaner.
Fix Container.input_map for same_input systems
drakeFunction.Root -> drakeFunction.DrakeFunction
Add drakeFunction.frames package

Currently contains only drakeFunction.frames.R, a method which returns a
singleton frame representing R^n for the specified n.
Add drakeFunction.kinematic package

Currently contains one class (RelativePosition) and its test
Add documentation to some DrakeFunction classes
Move Container funcitonality into Concatenated.

This is the only Container we were going to need. The Container class has been
removed.
Fix missing semicolon in drakeFunction.Sum