Split physics.mechanics examples into multiple files.
Edited the docstring for ReferenceFrame.orient().
Changed title to be consistent with other Physics/Mehcanics titles.
Got bicycle example working by adding a q3 dynamicsymbol.
Gave the rolling disc image a more descriptive file name.
Gave the rolling disc image a more descriptive file name.
Gave the rolling disc image a more descriptive file name.
Updated documentation to reflect change in figure file name.
Got all physics mechanics tests to work again, in part by splitting them into more files.
Got all physics mechanics tests to work again, in part by splitting them into more files.
Fixed doctest fail because of unnecessary newline.
Attempt to fix doctest fail resulting from Vector.simp having an unexpected value.
Attempt to fix doctest fail resulting from Vector.simp having an unexpected value.
Modified simplification in sympy.physics.mechanics doctests so that doctests pass when run together.
Merged conflict again.