#9 Adapt code to love2d 11.0

##### Originally PR#9 by pgimeno in GitHub, 7 Apr 2018 19:16 CEST This introduces a new colour component range mode, which defaults to `"native"`. The other possible value is 255. In native mode, the colour components used for styles use the same range as the version of LÖVE being used, be it 0-255 or 0-1. In 255 mode, the colour components use always the range 0-255 regardless of the version running. See https://notabug.org/pgimeno/Gspot/wiki/Implementation for usage details. *Commits: 4387d5c, 21bc143, cffaaa6* *pgimeno merged commit 8e85770 into master on 10 Apr 2018 20:01 CEST* *pgimeno deleted the love11 branch on 10 Apr 2018 20:03 CEST*