Fixed slideshow description typos.  #1557

Fixed text typos.

@tcheng001, I tried to fix the randomize option but it's working as far as I can tell.  It doesn't play the slides in a random order.  They'll still play 1, 2, 3, 4, 5, etc.  But the order is shuffled before the slides are added.  So which slide is 1 and which slide is 2 will vary when you load the page.

To test, create a slideshow with at least 4 slides.  Memorize their order.  Refresh the page.  Did they keep that order or get a different one?
Removed extra buttons from slideshow edit.  #1557

Preview and diff weren't really necessary for the slideshow.  Getting either of them to display properly would be more effort than they're worth.  It'd be lovely to do that some day, but for now I'd rather not offer them.
Fixed slideshow imagecrop.  #1557

The hook to change crop size wasn't working in 3.3.  Not sure if it was fragile to begin with or had something to do with media changes.  This fixes @gcaro's problem.

Fixed it.  Re-rolled the imagefield_crop patch and sent it to d.o.

Also found a hardcoded pixel size, so I removed that and used my region size function to get the max size.
Merge pull request #1781 from openscholar/1557-qa

1557 slideshow qa, merged likt is is hot.  
Applies patch from: http://drupal.org/node/1915510