Using a soname makes it easy for applications to
detect if the ABI of libcriu.so has changed.
It still creates libcriu.so as before in lib. During
'make install' additional links are created:

 libcriu.so -> libcriu.so.1.0
 libcriu.so.1 -> libcriu.so.1.0
Signed-off-by: Adrian Reber <adrian@lisas.de>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>