[Commits] [wesnoth/wesnoth] 8ee8ca: Rename addition operators to regular function

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/wesnoth/wesnoth
  Commit: 8ee8ca6786ceb7f37a5e78d5b026aea954ecbc9a
      https://github.com/wesnoth/wesnoth/commit/8ee8ca6786ceb7f37a5e78d5b026aea954ecbc9a
  Author: Celtic Minstrel <CelticMinstrel at users.noreply.github.com>
  Date:   2016-11-26 (Sat, 26 Nov 2016)

  Changed paths:
    M src/sdl/color.hpp

  Log Message:
  -----------
  Rename addition operators to regular function

Recommended by @Aginor as other blending functions may also be desired.
This also adds static_casts to silence potential conversion warnings.