audio/musicpc: Update to 0.29

Port changes:

• Changed to DISTVERSION
• Now uses meson instead of configure/make
• Added the MANPAGES option, manpage now is built by py-sphinx
• Removed targets that are now done by meson

PR: 226219
Submitted by: Zsolt Udvari <uzsolt@uzsolt.hu> (maintainer)
Approved by: tcberner (mentor, implicit)
Differential Revision: https://reviews.freebsd.org/D14531