Detach from musl libc process

[iapaddler]

Handle the console I/O distinctly.

[iapaddler]

Test:
Start an Alpine container:
% cd appscope/test/integration
% make alpine-shell

Start Apache scoped:
% export SCOPE_EVENT_DEST=file:///opt/test/logs/events.log
% ldscope httpd -k start

In a second terminal:
% cd appscope/test/integration
% make alpine-exec
% tail -F /opt/test/logs/events.log

Validate that events are emitted as expected:
% curl -k https://localhost:443/
View events in the second terminal defined above

Detach from Apache:
% ps -ef | grep httpd (get a list of pids for httpd)
% ldscope --detach <pids> (run once for each httpd pid)

Validate that no events are emitted:
% curl -k https://localhost:443/
View events in the second terminal defined above