This changes colorramp_fill() to base the ramp calculations on the
existing values in the supplied tables, instead of basing it on a pure
`i/size` value computed on the fly.
All gamma adjustment methods are changed to explicitly initialize the ramps
to the `i/size` value before calls to colorramp_fill().
Changes all set_temperature function in gamma adjustment methods
to take a color_setting_t pointer with the color settings.
Colorramp functions are similarly changed to take a color settings
struct.
This should fix a bug where command line options for the "manual" location
provider cannot override the config file. To keep compatability with previous
versions the command line parser will still special case parsing "-l LAT:LON"
and set the correct options in "manual".
Jon Lund Steffensen