Add Apache license header to main.c

Signed-off-by: Andy Grover <agrover@redhat.com>
Rough-in the device event code and handler interface

Add tcmu-runner.h, which handlers will compile against.

Signed-off-by: Andy Grover <agrover@redhat.com>
Rough-in handler loading

Going to try using dlsym directly on the tcmu_handler struct that each
handler must have, instead of calling a registration function. Simpler?
Unless there's a reason everyone does it the other way, in which case
we'll find out shortly :)

Currently searching in the current directory for files named "handler_*".

Signed-off-by: Andy Grover <agrover@redhat.com>
Add .gitignore

Signed-off-by: Andy Grover <agrover@redhat.com>
Add a basic makefile

Fix some printf stuff that showed up.

Signed-off-by: Andy Grover <agrover@redhat.com>