Reorganising classes and changing the way MCMC moves are handled.
Still finishing off implementing structural reorganisation.

The following MCMC moves still need to be sorted out:

* nu, sigma2Hier and sigma2 (non-global)

* joint alignment + rotation subtree moves
Almost finished with the reorganisation. Still need to 

* Skip sigma2 update for root
* Create classes for subtree moves
* Replace angleP and xlatP with member variables of the
RotationOrTranslationMove class
All done except StructTrace.java.
Alteration to the way ParameterInterface is used.
Implementation finished. Now correcting minor bugs.
Removed AlignmentRotationCombinationMove as its unnecessary.
Some small bug fixes, and also removed the need for casting the 'owner',
by only introducing this field for a subclass of McmcMove, namely
StructAlignMcmcMove.
This branch now running, with results looking reasonable. 

To do:

1) Fix GUI (currently tries to access acceptance rates via a method that
was removed)
2) Test against main structalign branch to make sure everything is
behaving in the same fashion.
StructAlign GUI now working with new version.
Added weights to MCMC moves, and the results look very similar to with
the previous version. Still need to test with exactly the same weights
to see if there is any difference.
Added a comment.
Added automatic tuning for rotation, translation and library moves.
Library seems to be always rejected though.
Corrected a typo.
Print statements.
Changes to move weights.
Merge branch 'structalign' of ssh://github.com/statalign/statalign into structalign