Add build/pkg-install.sh.

Compile latest release tag and install it as pkg-config package.

build/pkg-install.sh

@@ -0,0 +1,45 @@
+#!/bin/sh
+
+set -e
+
+_IFS="$IFS"; IFS=':'
+for dir in $PKG_CONFIG_PATH `pkg-config --variable pc_path pkg-config`; do
+    if [ -d "${dir}" -a -w "${dir}" -a -d "${dir}/../../include" ]; then
+        DST="$dir"
+        break
+    fi
+done
+IFS="$_IFS"; unset _IFS
+
+if [ -z "${DST}" ]; then
+    echo "no suitable pkg-config directory found."
+    exit 1
+fi
+
+if [ `basename $0` = "pkg-install.sh" ]; then
+    SRC=`dirname $0`
+    SRC=`(cd $SRC/..; [ -d .git ] && pwd)`
+fi
+
+export DST
+cd ${TMPDIR:-/tmp}
+
+trap 'rm -rf blst.$$' 0
+git clone ${SRC:-"https://github.com/supranational/blst"} blst.$$
+( trap '[ $? -ne 0 ] && rm "${DST}/blst.pc" 2>/dev/null' 0
+  cd blst.$$
+  tag=`git tag --sort=v:refname | tail -1`
+  git checkout --detach ${tag}
+  ./build.sh "$@"
+  cp libblst.a "${DST}/.."
+  cp bindings/blst.h* "${DST}/../../include"
+  cat > "${DST}/blst.pc" << blst.pc
+libdir=\${pcfiledir}/..
+incdir=\${pcfiledir}/../../include
+Name: blst
+Version: $tag
+Description: blst core library
+Cflags: -I\${incdir}
+Libs: -L\${libdir} -lblst
+blst.pc
+)