added optional config parameter fixedOpacity
if not set, the library works as before
valid values are between 0 and 255. these values may be considered more awkward than values between 0 and 1. I decided to simply use what was used in the rgba colors.
added optional config parameter fixedOpacity if not set, the library works as before valid values are between 0 and 255. these values may be considered more awkward than values between 0 and 1. I decided to simply use what was used in the rgba colors.