use 5.6 instead of requiring it; avoids accidentally compiling the stuff.
No obvious way to dodge the deprecated-our bug in 5.005; so, require 5.6 and be done with it.
Repair MANIFEST.
Add minimal tests.
Testing this thing will require forking a job to wait for the signal, signaling it, and watching for the output. Given the lack of fork on some systems this will not be trivial.
Initial version