Release 2016.36

Dan fixed the sound mixer icon, yeah!
keith added value curves to another 6 effects.
Dan fixed the background image
Gil added new effect "fill"
some bug fixes


Latest releases are found at http://nutcracker123.com/nutcracker/releases/
Issue Tracker is found here: https://github.com/smeighan/xLights/issues

XLIGHTS/NUTCRACKER RELEASE NOTES:
---------------------------------
2016.36 Jun 06, 2016
-- enh (keithsw) Change backup files to *.bkp extension to minimize risk of users opening them accidentally. Include them in F10 backup.
-- bug (dkulp) Don't use OpenGL 2.1 if context is 2.0
Use glMapBufferRange instead of glBufferSubData (latter is SLOOOW on ATI cards)
-- bug (dkulp) fix the background image button not working
-- bug (dkulp) Update borders for singlestrand
-- enh (dkulp) Strip out the defaults for the On/ColorWash and buffer/layer/color panels at load time. Reduces file size
-- bug (dkulp) Use an icon bundle with different sized icons to hopefully fix the volume meter issue on windows
-- bug (keithsw) Fix custom value curves not being editable when you re-open them
-- enh (keithsw) Value curves added to single strand, garlands, fire, plasma, curtain. color wash
-- bug (keithsw) Fix tendril effect
-- bug (keithsw) Fix custom value curves not being editable when you re-open them
-- bug (keithsw) When changing value curves use a sensible set of defaults.
-- enh (chrisD) Add menu items to load/save perspectives directly
-- enh (gil) Add new effect Fill.
-- enh Improve several effect toolbar icons.