Revert "mk/common-unix.mk: libs are installed non-executable"
Revert "mk/common-unix.mk: libs are installed non-executable"

This reverts commit 3658324b8ab401863cdda7b758589748bf78b5a8.

non-executable shared lib broke automatic dependencies in Fedora.
this manifested itself in packaging logdemux:

  "nothing provides libiniphile.so.0 needed by libiniphile-devel"

http://en.opensuse.org/openSUSE:Shared_library_packaging_policy says

  Shared libraries are normally not standalone runnable
  (exception: libc.so.6 and ld-linux.so.2). But they often
  have the +x bit set!

which, while correct, is far from the whole truth.

freenode/#opensuse-buildservice:

  2013-06-06 23:29:37 < vad> elfdeps only works on executable files.
                             Some stupid packages generate shared
                             libraries without the required x bit

roman-neuhauser/iniphile