support transition directives in rgb file

[Human]

Currently, Hugh can be told to use different transition parameters by changing hugh_config.ini, but this is not coordinated with changes to the rgb CSV file.

• Add support for specifying an override in the rgb file to the general transition configuration in hugh_config.ini

Current example (red at 100%)
255, 0, 0

Future example (red at 100%, no instant transition, fade through black, 127 increments of change)
255, 0, 0, 0, 1, 127

(Or possibly True and False instead of 1 and 0.)

[Human]

Implement simultaneously with #3