Changed how SA requests are handled from user-mode. Synchronous requests

Changed how SA requests are handled from user-mode.  Synchronous requests
now use synchronous IOCTL processing rather than blocking in user-mode and
waiting for the IOCTL completion callback.  This eliminates the potential
for deadlocks resulting from clients making synchronous SA queries from
a callback thread context.

git-svn-id: svn://openib.tc.cornell.edu/gen1@23 ad392aa1-c5ef-ae45-8dd8-e69d62a5ef86