Include in search option

[nullromo]

There should be a toggleable option for each cash register on whether or not to include it in searches. So if cash register 1 has foo, and cash register 2 has bar, and both are toggled on, then the search would behave as if it were foo\|bar. Pressing n would find the next instance of foo or bar, whichever is closer. If this option were toggled off for cash register 2, then pressing n would just go to the next foo.

This more or less supersedes the "active" cash register notion. Instead of one "active" cash register, multiple can be active at a time. But I guess the active one is still the one that gets edited when you press / for example.