audio/csound6: Take maintainership; Change to github

This port is broken. It both failed to fetch and failed to build afterwards.
I fixed the fetching problem: it moved to github.
So far I couldn't fix the build problem - it seems to fail due to some incompatibilities
with dependencies, but it is also badly outdated. New version doesn't build either.

The upstream needs to fix at least these two problems:
* https://github.com/csound/csound/issues/1063
* https://github.com/csound/csound/issues/1064

I'll come back to it after they fix these build issues.

audio/csound6/Makefile

@@ -2,15 +2,13 @@
 # $FreeBSD$
 
 PORTNAME=	csound
-PORTVERSION=	6.06
+PORTVERSION=	6.06.0
 PORTREVISION=	19
 CATEGORIES=	audio lang
-MASTER_SITES=	SF/${PORTNAME}/${PORTNAME}6/${PORTNAME:S/c/C/}${PORTVERSION}
 PKGNAMESUFFIX=	6
-DISTNAME=	${PORTNAME:S/c/C/}${PORTVERSION}
 DIST_SUBDIR=	csound
 
-MAINTAINER=	ports@FreeBSD.org
+MAINTAINER=	yuri@FreeBSD.org
 COMMENT=	Sound synthesizer
 
 LICENSE=	LGPL21+
@@ -26,6 +24,7 @@ LIB_DEPENDS=	libsamplerate.so:audio/libsamplerate \
 
 USES=		alias bison cmake:outsource,noninja eigen:3 localbase python:2.7
 # math/gmm++ requires c++11
+USE_GITHUB=	yes
 USE_CXXSTD=	c++11
 CMAKE_ARGS=	-DBUILD_CSOUNDVST:BOOL=OFF \
 		-DBUILD_JAVA_INTERFACE:BOOL=OFF \

audio/csound6/distinfo

@@ -1,2 +1,3 @@
-SHA256 (csound/Csound6.06.tar.gz) = 03e6542d60eaffc9b4c5e81f36243e8872dedbe94c036adaa8e07c27938feb11
-SIZE (csound/Csound6.06.tar.gz) = 27232172
+TIMESTAMP = 1542475461
+SHA256 (csound/csound-csound-6.06.0_GH0.tar.gz) = ce01dbf249eb6cf27e3090b8d9aa7d779256a364707ce0b81f7545dc168d9d50
+SIZE (csound/csound-csound-6.06.0_GH0.tar.gz) = 33089325