Disable PV on SystemCore

[samfreund]

PV takes up a lot of resources, and that's fine when it's running on a coproc. When on the main robot controller, that could cause a lot of unintentional consequences that we don't want to see happen.

[samfreund]

Whether the device is syscore is to be determined by the existence of a /home/systemcore directory.

[samfreund]

For bonus points, a little blurb in the quick-start about no support.

[mcm001]

There are lots of other systemcore-only files we could pull from

• /var/www/html or /var/www/htmlblocks
• if there is a systemcore user
• if there is a systemcore group

[samfreund]

There are lots of other systemcore-only files we could pull from

• /var/www/html or /var/www/htmlblocks
• if there is a systemcore user
• if there is a systemcore group

Up to your discretion as to what you think the best approach, I just picked something that I know is easy to check and we know will work.