Replace import of Foreign with System.IO.Unsafe for unsafePerformIO in Pixel.hs.

"Foreign" no longer provides 'unsafePerformIO'.
In Pixel.hs, replace lens with lensGS.

This is since fc-labels recently changed lens to take a getter and a modifier
rather than a getter and a setter.
Replace import of Foreign with System.IO.Unsafe for unsafePerformIO in Data/Bitmap/Foreign.hs.

Also correct alignment in module imports from the same file.
Oops, forgot to update CHANGELOG!  Fix.
Improve formatting of CHANGELOG for in-development version.
Support bitmap-0.0.2, replacing "newBitmap" with "newIOBitmap".

This also changes a type alias to be bound to 'FB.IOBitmap' rather than
'FB.Bitmap'.

Also add version constraint on "bitmap" dependency, because of this major API
change that does not conform to cabal's package versioning policy.

Also includes the following additional changes:
 * Removes import of Data.Bitmap.
 * Replaces 'withBitmap' with 'withIOBitmap'.
Hide import of 'get' from Conrol.Monad.Record, and add version constraint to monad-state dependency.
Remove redundant import of Data.Bitmap.Searchable from Data.Bitmap.String.Internal, fixing warning.
Hide import of get from Control.Monad.Record in StringRGB24A4VR/Internal.hs.
Fix typo in changelog.
Hide import of get from Control.Monad.Record in StringRGB32/Internal.hs.
Bump version to 0.2.6.3 from 0.2.6.2.