Fix broken .config/git-annex/program installed by standalone tarball.

It was doubly broken; both missing a slash, and containing
"runshell git-annex", while some parts of the code expected it to be a
simple path to a program. This appears to include the transfer queue
runner, and the code that starts a new assistant process when switching to
another repository in the webapp.

standalone/linux/git-annex

@@ -0,0 +1,25 @@
+#!/bin/sh
+base="$(dirname $0)"
+if [ ! -d "$base" ]; then
+	echo "** cannot find base directory (I seem to be $0)" >&2
+	exit 1
+fi
+if [ ! -e "$base/runshell" ]; then
+	echo "** cannot find $base/runshell" >&2
+	exit 1
+fi
+
+# Get absolute path to base, to avoid breakage when things change directories.
+orig="$(pwd)"
+cd "$base"
+base="$(pwd)"
+cd "$orig"
+
+# If this is a standalone app, set a variable that git-annex can use to
+# install itself.
+if [ -e "$base/bin/git-annex" ]; then
+	GIT_ANNEX_APP_BASE="$base"
+	export GIT_ANNEX_APP_BASE
+fi
+
+"$base/runshell" git-annex "$@"