xx 2017.21 released

[sean]

xLights 2017.21 released.
Keith fixed some troublesome bugs from 2017.20

Latest releases are found at www.xlights.org
Videos tutorials are found at videos.xlights.org
Forums are located at nutcracker123.com/forum
Issue Tracker is found here: www.github.com/smeighan/xLights/issues

XLIGHTS/NUTCRACKER RELEASE NOTES:
---------------------------------
 
2017.21  Jul 28, 2017
   -- enh (keith)   Add the block of channels model
   -- enh (keith)   Add option to display fades as ramps on the On effect and Twinkle effect ...
                    mainly for use in AC mode
   -- bug (keith)   Fix a bunch of bugs with AC mode
   -- bug (keith)   Fix #882
   -- bug (keith)   Fix problem with oversize buffers crashing xLights