Split physics.mechanics examples into multiple files.
Edited the docstring for ReferenceFrame.orient().
Merge branch 'mechanicsdoc'
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.
optimized loop over subsets in ``dup_zz_zassenhaus``

In this commit factorization is much faster than in master when
the loop over the subsets is long; e.g. with

``minpoly(S('sqrt(1 + 2**(1/5)) + 2**(1/5)*sqrt(1 + 2**(1/5))'), x)``

the resultant has degree 100; it is factored 150x faster in this commit
than in master; the loop over subsets has 6e5 cases, but only 1000
of them pass the test on the constant term.
In this commit it is attempted to choose ``p`` such that there are
fewer factorizations over Z_p[x]. There is a small overhead for this.
faster ``swinnerton_dyer_poly`` using ``minimal_polynomial``
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.