Run ldconfig on make install as it is required to use the plugins compressd and zlibvalid.

This fixes the warnings:

 WARNING: Failed to load plugin module 'compressd': libcompress42.so: cannot open shared object file: No such file or directory

 WARNING: Failed to load plugin module 'zlibvalid': libtinfl.so: cannot open shared object file: No such file or directory
Merge pull request #33 from liske/ldconfig

Run ldconfig on make install as it is required to use the plugins compre...