Changelog for haskeline-0.6.2

Changed in version 0.6.2: User interface changes: * A multitude of new emacs and vi commands * New preference 'historyDuplicates' to prevent storage of duplicate lines * Support PageUp and PageDown keys * Let ctrl-L (clear-screen) work during getInputChar Internal/API changes: * Compatibility with ghc-6.12 * Calculate the correct width for Unicode combining characters * Removed RankNTypes requirement; added Rank2Types and UndecidableInstances * Use simpleUserHooks instead of autoconfUserHooks in the Setup script * Internal refactoring to make command declaration more flexible * Read the .haskeline file completely before starting the UI (laziness issue)