add additional shared libraries (#137)

* This merge request gives the ability to add shared libaries without set LD_LIBRARY_PATH variable.

 1. Generate file in /etc/ld.so.conf.d/
 2. update /etc/ld.so.cache with ldconfig command

example pillars:

linux:
  system:
    enabled: True
    ld:
      libraries:
        java:
          - /usr/lib/jvm/jre-openjdk/lib/amd64/server
          - /opt/java/jre/lib/amd64/server

* fix format in README.rst for Shared Libraries

* Fix for #137 - change pillar libraries key to library
3 files changed