mkrelease.sh: use robust HEAD==master check that also handles detached heads
mkrelease.sh: add helper function match() for string pattern matches
mkrelease.sh: use $MKRELEASE_SKIP to skip certain ops for debugging
mkrelease.sh: version increment, history moved to git
mkrelease.sh: remove inherently insecure shellvar command
mkrelease.sh: allow skipping of clean working tree check
mkrelease.sh: parse MKRELEASE_UPLOAD_URL and MKRELEASE_REVISION_VAR from Makefiles
mkrelease.sh: upload tarball before bumping revision
mkrelease.sh: rollback checked out tree after version bump
mkrelease.sh: use unwrapped message body to fix some commit messages
mkrelease.sh: allow customization of the ChangeLog output filename
mkrelease.sh: LICENSING: clarify CC0 Public Domain dedication
mkrelease.sh: check versioning before tarball checks
mkrelease.sh: adjust post-release 'master' and 'devel' branches for devel versioning
BUILD: update release upload path
BUILD: simplify version handling, use just BST_VERSION and variants
mkrelease.sh: change -E CONFIGUREAC to increment AC_INIT version arguments
BUILD: pass -E configure.ac to mkrelease.sh
BUILD: use version 0.8.3-rc0 for test builds
mkrelease.sh: exclude release commit from 'news' listing