Fix British English spellings
dialogue      -> dialog    (when referring to GUI window items)
analogue      -> analog
color[s]      -> colour[s]
colorspace    -> colourspace
visualization -> visualisation
normalize     -> normalise
Harddisk      -> Hard disk (consistent with all other usage of "[Hh]ard disk")
disc          -> disk      (context: magnetic media)
disk          -> disc      (context: optical media)

'colourspace' -> 'colour space' nitpick
Merge pull request #3269 from FernetMenta/aefixes

Audio mode change
Merge pull request #3261 from MilhouseVH/english-fix

Fix British English spellings
paplayer: fix gapless playback of cue sheets
PaPlayer: Fix crossfade song change for audio cds
[win32] fix remarks about default build
ActiveAEStream: Fix Compiler warning (thx @vdrfan)
 ActiveAE: fix flushing engine on pause after 1a01f4409bed6e2d4d6a0e3149a20ea5fff9c07a
videoplayer: adapt lateness detection and dropping to buffering
video player: present correct pts to user for a/v sync (after buffering in renderer)
videoplayer: some rework and documentation
renderer: bump buffers to 5
videoplayer: update frametime, it might change due to fps detection
videoplayer: give streams with invalid fps a chance for fps detection
dvdplayer: allow rewinding at end of stream, do a seek after rewind
X11: ditch SDL for video and window events
X11: Add xbmc icon
X11: add SDL joystick until we have a better solution
X11: factor out code handling device reset notification
X11: move xrandr events to WinEventsX11