Ticket 48982 - Enabling a plugin that has a versioned so causes overflow
    
    Bug Description:  Enabling a plugin that has a versioned.so causes overflow.
    This is becuase we assumed that all plugins are "libname.so", and were not
    symlinks. So we used a fixed size buffer to realpath.
    
    Fix Description:  Realpath can dynamically allocate the correct size buffer
    for the resolved path, so we use that. Additionally, we need to use "free" instead
    because realpath uses malloc not slapi_ch_malloc.
    
    https://fedorahosted.org/389/ticket/48982
    
    Author: wibrown
    
    Reviewed by: nhosoi (Thanks so much!)