dev-tex/biblatex: add biber use flag

biber is the default backend for biblatex for several versions now and
supersedes the old bibtex and bibtex8 backends.

Package-Manager: Portage-2.3.5, Repoman-2.3.2

dev-tex/biblatex/biblatex-3.7-r1.ebuild

@@ -0,0 +1,40 @@
+# Copyright 1999-2017 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=6
+
+inherit latex-package
+
+DESCRIPTION="Reimplementation of the bibliographic facilities provided by LaTeX"
+HOMEPAGE="http://www.ctan.org/tex-archive/macros/latex/contrib/biblatex https://github.com/plk/biblatex/"
+SRC_URI="mirror://sourceforge/${PN}/${P}.tds.tgz"
+
+LICENSE="LPPL-1.3"
+SLOT="0"
+KEYWORDS="~amd64"
+IUSE="+biber doc examples"
+
+DEPEND="dev-texlive/texlive-bibtexextra
+	dev-texlive/texlive-latexextra
+	dev-texlive/texlive-genericextra"
+RDEPEND="${DEPEND}
+	biber? ( ~dev-tex/biber-2.7 )"
+
+S="${WORKDIR}"
+TEXMF=/usr/share/texmf-site
+
+src_install() {
+	insinto "${TEXMF}"
+	doins -r bibtex tex
+
+	dodoc doc/latex/biblatex/{README,CHANGES.org}
+	if use doc ; then
+		pushd doc || die
+		latex-package_src_doinstall doc
+		popd || die
+	fi
+
+	if use examples ; then
+		dodoc -r doc/latex/biblatex/examples
+	fi
+}

dev-tex/biblatex/metadata.xml

@@ -13,6 +13,9 @@
 		<email>[email protected]</email>
 		<name>Gentoo TeX Project</name>
 	</maintainer>
+	<use>
+		<flag name="biber">Install the unicode compatible backend processor</flag>
+	</use>
 	<upstream>
 		<remote-id type="github">plk/biblatex</remote-id>
 		<remote-id type="sourceforge">biblatex</remote-id>