Support --no-color and --color flags

[devinivy]

These flags are handled by the supports-color package—we just need to ensure they don't cause bossy to complain. Might need special handling for hpal run.

[wswoodruff]

Tested this out locally, the setting is handled correctly by the supports-color package but bossy tracks those flags as arguments; should we explicitly strip those out of args?

[devinivy]

We want those flags to decide whether hpal and hpal-debug provide colored output, and we want hpal run commands to do with those flags whatever they wish. So in short, they can't simply be stripped out of args if those same args are going to be passed along to an hpal run command. It's a slightly hairy problem to solve.

[jdonisvitch]

Is the value of this feature worth the effort?

[wswoodruff]

Got a proposal for this here #46