Refactor facultymatt's refactoring of postmaster's unsolicited check

Refactored @facultymatt 's refactor of postmaster's unsolicited check.

Also tweaked forceClear such that the sending of multiple SMS-es back to back should (hopefully) not be blocked anymore.
You want something like this instead https://github.com/tessel/cli/blob/master/src/logs.js#L5

This way you can do `._debugPrint("arg1", 1, "2", 3)`