WRKSRC. LIBTOOL_OVERRIDE defaults to "libtool */libtool and */*/libtool,"
meaning that, in most packages, there's no need to set it.
So: Nuke tons of LIBTOOL_OVERRIDE=${WRKSRC} and adjust a few
SHLIBTOOL_OVERRIDEs (remove ${WRKSRC} from them).
Package provided by Chris Wareham <chris.wareham@btinternet.com> via PR
pkg/21929.
Shared library for Hydrogen, a simple real-time Drum machine/sequencer
for CAC (Computer Aided Composition).