Moved many things to Login.js

Resolves #1112.

http://jenkins.buttonweavers.com:8080/job/buttonmen-AdmiralJota/399/

In addition to the tests for whether or not the player is logged in, I also moved a bunch of common code from the ```Foo.showFooPage()``` and ```Foo.arrangePage()``` methods in the individual files to ```Login.arrangeHeader()``` and ```Login.arrangePage()``` so that it can be shared. 

Most pages don't even need their own ```arrangePage()``` method anymore (so I took them out, just having them call ```Login.arrangePage()``` instead), and there are several pages where we should probably merge ```Foo.showFooPage()``` with ```Foo.getFoo()``` at some point, since there's so little there now.
So... i am super lazy and haven't tested this, because i'd have to roll back to an older version and load all the pages and roll forwards again and i am *just so lazy*.  But it looks to me like this does not address the concern about people updating from older versions of the pages --- i think when this is rolled out, every player will get a blank page on every page of the site they've visited before, and will need to force-reload them all.  It seems to me that this could be easily avoided by adding an else clause to the relevant block, which i believe is this block, suggesting that people reload.

If you think you addressed this, let me know, and i'll quit being so lazy and test it.  But i don't think you mentioned it in your commit messages, and it doesn't look addressed to me at a glance.