Changed Force to Actuation for all relevant Actuator's member functions
(to make naming more consistent and descriptive; including fcns as getForce, setForce,
computeOverrideForce, overrideForce, isForceOverriden, setOverrideForce, getOverrideForce)
Merge latest master to ForceToActuationRename branch
Added more explanation to getStress comments.
Adjusted some spacing
Renamed variable force to actuation in TorqueActuator::computeForce
(to clarify actuation is being overridden not force)
Removed comments left to check QueryPerformanceCounter
(as it's not used anymore and we just use e.g. std::clock_t startTime = std::clock();)
Renamed output actuation to use lowercase
(to be compatible with conventions)
Removed doxygen-style comments in Actuator.cpp and kept only internal comments.
Updated ScalarActuator comments to reflect the Rename
Updated actuation signals to actuation.
changed some API references to get/set Force()
replaced setForce with setActuation
changed back to getForce
Fixes to bugs I introduced when removing anchorBody and anchorTransform from RigidFrames.  Also, bug fixes in making comparisons in testFrames.  Specifically:

1. correct transposition when calculating a FixedFrame's transform.
2. removed vestigial references to getAnchorBody() and other "Anchor" based methods.
3. converted uses of c++ built in assert to our ASSERT when making comparisons in testFrames.  unlike assert, ASSERT will do comparisons in both release and debug builds.
New branch to obtain internal consistency with all components call Super::connectToModel(), Super::addToSystem, etc... so that any component can serve as a proper example.
Made all Components adhere to Super::connectToModel. Ligament, PathSpring and ControllerSet were  exceptions to the rule and now they are compliant.

The rule for Super::finalizeFromProperties() is that it should be called last and this was also enforced.
Eliminated overrides with just Super::<do>.
Joints and Model are currently the only exceptions to the rule that Super::addToSystem() must be called first in all addToSystem implementations.

The model must set up the controls cached before Actuators can establish their indices within the Model cache. For Joints, the mobilized body of the Joint must be added (e.g. defined) before the Coordinates can determine their coordinate related indices.

For all other Components, calling Super::addToSystem() first works. We can continue insist that the API is broken (@sherm1) or we can document the reasons for these exception, which seem reasonable to me.
update and merge from master
Merge pull request #209 from opensim-org/ForceToActuationRename

Rename "Force" to "Actuation".