Backend select dialog now handled manually
Added displayName to backends - used for selection dialog
Backend selection now saved with provider name
Added currentSpeed() to TTSBackendBase, works like currentVoice()
Added XBMCAudioTTSBackendBase backend base
Added ESpeak_XA_TTSBackend which uses subprocess and XBMC audio and implements currentSpeed()
Added a fix for OK speaking as Oklahoma
Settings now only shows 'Voices' option for the currently displayed speech engine