[kovidgoyal]

Released version 2.99.13 with the following changes:

1. Allow clicking on the calibre version in the status bar to see what's new in the current calibre release
2. Fix Page flips options box in viewer preferences not being laid out properly
3. Fix get saved search expression not working if there is a leading =
   
4. Add a sort button that shows up only when the Cover grid is displayed
5. Fix initial down arrow in search box jumping two places
6. Tighten up spacing in the main window and remove the unnecessary border between the tool bar and the rest of the window

@acidslam: This release also has Qt compiled to load opengl dynamically. That *might* allow it to work without the opengl dll, since calibre itself does not use opengl -- it depends on what Qt does about delay loading that dll.