more pkgsrcesque.
1) turn _USE_GITHUB into an internal infrastructure variable
2) put back MASTER_SITES in packages' Makefiles.
3) encode the account in the master site URL, remove GH_ACCOUNT
4) rename GH_PROJECT to GITHUB_PROJECT
5) rename GH_TAGNAME to GITHUB_TAG and allow it to accept commit hash
as well as tag. GH_COMMIT is gone.
6) turn on this functionality when MASTER_SITES matches a predefined github
pattern instead of via explicit USE_GITHUB setting.
handling less painful.
See: https://www.freebsd.org/doc/en_US.ISO8859-1/books/porters-handbook/makefile-distfiles.html#makefile-master_sites-github
To use, set in Makefile:
DISTNAME= exampleproject-1.2
USE_GITHUB= YES
The following variables alter USE_GITHUB behavior:
GH_ACCOUNT defaults to PKGBASE
GH_PROJECT defaults to PKGBASE
GH_TAGNAME defaults to PKGVERSION_NOREV
(sometimes you want to override with v${PKGVERSION_NOREV})
GH_COMMIT explicit commit hash if no tag is available
GH_RELEASE default empty, may be set to ${DISTNAME} for example
GH_TYPE overrides the autodetected MASTER_SITE URL scheme
