Tidyup: moved some replay globals out of header, renaming some others

Global items renamed (and moved from middle of .cpp file to top, only used
within class file):
QAction * actionSpeedDisplay    ==> pActionSpeedDisplay
QAction * actionReplayTime      ==> pActionReplayTime
QLabel * replaySpeedDisplay     ==> pReplaySpeedDisplay
QLabel * replayTime             ==> pReplayTime
QTimer * replayTimer            ==> pReplayTimer
QToolBar * replayToolBar        ==> pReplayToolBar

Global items moved out of class header (as not used outside of class files):
QAction * actionReplaySpeedUp   ==> pActionReplaySpeedUp
QAction * actionReplaySpeedDown ==> pActionReplaySpeedDown

Signed-off-by: Stephen Lyons <slysven@virginmedia.com>