rigid body visualizers should have the position frame as input (the state frame will automatically transform down to position if that is passed in, so it should not break backwards compatibility)
per the discussion at the triage meeting, we can count on the constraint eval function to use geval if and only when necessary, so we should be absolutely call positionConstriants, velocityConstraints, and stateConstraints on a manipulator without geval.

note: changed the default grad_method to 'user_then_taylorvar', which means that constraints must declare that they have gradient information to avoid hitting geval.  there might be some in the current examples that do not do this.
default constraint grad_method is ''
should not have had pause commands in a unit test
another pause. :(
handle empty grad_method
Merge pull request #496 from RussTedrake/visualizer_frame

rigid body visualizers should have the position frame as input (the stat...
Merge branch 'geval_constraints' of https://github.com/RussTedrake/drake into RussTedrake-geval_constraints

Conflicts:
	examples/RimlessWheel/runDircol.m
Merge branch 'RussTedrake-geval_constraints'
Merge branch 'master' into hand_grasping_demo
add RelativeFixedPositionConstraint