play: add viber support

prescription.d/viber.sh

+#!/bin/sh
+
+# TODO: common place
+fatal()
+{
+    echo "FATAL: $*" >&2
+    exit 1
+}
+
+PKGNAME=viber
+
+if [ "$1" = "--remove" ] ; then
+    epm remove $PKGNAME
+    exit
+fi
+
+[ "$1" != "--run" ] && echo "Install Viber for Linux from the official site" && exit
+
+[ "$($DISTRVENDOR -a)" != "x86_64" ] && echo "Only x86_64 is supported" && exit 1
+
+
+# the same binaries in deb and rpm
+PKG="https://download.cdn.viber.com/cdn/desktop/Linux/viber.deb"
+
+epm install "$PKG"

repack.d/viber.sh

+#!/bin/sh -x
+# It will run with two args: buildroot spec
+BUILDROOT="$1"
+SPEC="$2"
+
+mkdir -p $BUILDROOT/usr/bin/
+ln -s /opt/viber/Viber $BUILDROOT/usr/bin/viber
+ln -s /opt/viber/Viber $BUILDROOT/usr/bin/Viber
+subst 's|%files|%files\n/usr/bin/viber\n/usr/bin/Viber|' $SPEC