Dynamic linker fixups

I've only been able to make this work on Linux so far (but see below) and I'm not 100% convinced that linking against a specific .so is a good idea so feedback is welcome.

So far, I've only been able to make it work on OS X when I execute `install_name_tool -id @rpath/libocci.dylib /path/to/libocci.dylib` first, else `-Wl,-rpath,<path>` has no effect...

/cc @raymondfeng