cp .so libs to install target

- preserve symlinks
use point release for LIBSO

- e.g. libphobos2.so.0.64.2
- soname remains libphobos2.so.0.64
Merge pull request #1711 from dawgfoto/installSO

[install] cp .so libs to install target
Revert "use point release for LIBSO"

This reverts commit 5d630e52256f7360dde7c9bb79285939321735bc.