Changes each adjustment method to take a preserve parameter when
setting the temperature instead of parsing the preserve option
from the command line/configuration file. This helps resolve the
issues around #513:
- This allows the preserve option to be implemented as a
command-line switch (-P). This switch _disables_ the preservation
of existing gamma ramps. Having a command-line switch makes it
easier to use directly with manual or one-shot mode.
- The preserve options is on by default, so continual mode as well
as other modes will default to applying the color adjustment
on top of the current gamma ramps.
- Preserve is always disabled in reset mode so resetting works
as expected again.
Create options.c which contains functions for initializing and
parsing options from the command line and the configuration file.
Program options that were previously local variables in main() are
moved to the options_t struct.
Jon Lund Steffensen