FitRideFile: Use the slope value
Fix calendar hide/show crash

.. by hiding not deleting minicharts. Its better this
   way since deleting and recreating them all is very
   expensive and the layout code breaks as a result.
   It is an edge case for optimisation anyway.

.. so if you expand out the sidebar and have lots of
   minicalendars then shrink it down again then it
   will be slow to update.

Fixes #550.
Don't start in full screen]

If you close or crash in fullscreen mode then it is
restored on startup but not in fullscreen mode. So
it is impossible to shrink -- this is particularly
relevant on Windows 8.

We now restrict the initial size to always be 60px
smaller in x and y than the actual screen size.
Remove bubble from DiaryWindow

Now we have a decent sidebar calendar it is redundant
and furthermore it is fugly!!
UI Nits: Activity list cosmetic

Drives me mad, but the separator line was over painted
and it just looked amateurish. Been meaning to fix it for
absolutely ages!
Deprecate QtMacSearchBox

We now only use the SearchFilterBox on all platforms.
UI Nits: Search box clear icon

.. more like a Mac and better suited to rounded edges.
Fix white specs on Download Icon

.. only affected Windows and Linux.
UI Nits: Move searchbox toolbutton

.. to the right 2 pixels on Windows/Linux
   Seems obsessive but if I'm gonna look at this for the
   next year I want it to be perfect.