Add autodetection capability to Linux systems using musl

[cleydyr]

As a user of Linux OSes with musl (like the ones used in Alpine Docker images, see #44), I'd like the Dart Sass Maven Plugin to autodetect if the operating system uses musl.

[tubbynl]

something similar was implemented in sqlite for this problem: xerial/sqlite-jdbc#675 , but some research is required, i would expected there's a lib for this

[cleydyr]

Hey, @tubbynl. See #47 .