Experiments with multiple temperature stages

NinjaLAMP supports thermal profiles with multiple temperature stages. You can define a profile as an array of "Stage" struct. Each stage have two value, temperature in Celsius and duration in milliseconds. If the duration value is zero, it means that the stage lasts forever.

const int stagesCount = 3;
struct Stage stages[3] = {
  { 35.0, 20 * 1000 },
  { 45.0, 15 * 1000 },
  { 55.0, 0 },
};