Fix VMware Fleecing Issue with Missing Symlinks

Change VixDiskLibServer process LD_LIBRARY_PATH to use the
actual location of the VixDiskLib libraries. Remove old change
to modify the LD_LIBRARY_PATH of the smart_proxy_worker since it
no longer needs this.

https://bugzilla.redhat.com/show_bug.cgi?id=1122264
Remove temporary code for comparing C-binding with FFI-binding

VixDiskLib.rb in this current incarnation simply tested an environment
variable and then loaded the new FFI-binding to the library (the
default) or loaded the old C-language binding to VixDisklib.  We will
be removing access to the C-language binding so this file is no longer
needed.  Note that the next commit will rename VixDiskLibClient.rb,
which VixDiskLib.rb required in order to start the FFI-binding, back
to VixDiskLib.rb.
Replace temporary code FFI-binding code

The previous commit removed the file VixDiskLib.rb, which loaded either
the VixDiskLib FFI-binding or the C-language binding, based on an
environment variable.  We are removing access to the C-binding, so the
file VixDiskLibClient.rb, which starts the FFI-binding, is being renamed
to VixDiskLib.rb, so that the FFI-binding will always be used.
Remove VixDiskLibClient Log Message References

- Since VixDiskLibClient.rb was renamed to VixDiskLib.rb by the last
commit, this will change all references to "VixDiskLibClient" in log
messages printed in this file to "VixDiskLib".
- Remove the spec testing the command line for the smart_proxy_worker
since the change to the lib path is removed by the first commit in
this pull request.
Merge pull request #277 from jerryk55/vddk_ffi_symlink_fix

Fix Issues Related to Old VixDiskLib Symlink Workaround