Explicitly support building against libssh2 built with libgcrypt

Signed-off-by: James McCoy <vega.james@gmail.com>
Setup threading callbacks for gcrypt

Signed-off-by: James McCoy <vega.james@gmail.com>
Setup threading callbacks for OpenSSL

Signed-off-by: James McCoy <vega.james@gmail.com>
Add a timeout method applying to the whole session
Merge pull request #10 from jamessan/pu/threadsafety

Threading initialization for crypto libraries
Merge pull request #11 from zehkae/global_timeout

Add a timeout method applying to the whole session
add note to Makefile.PL instructions for gcrypt

Update for 5d6d7ef to note the new 'gcrypt' parameter to Makefile.PL in
the instructions and add a Changes entry.
Changes for 1321114, 19375d1 and 7dfc965
release 0.47
Win32 compatibility fix
make SSH2.xs build under non-threaded perls

- swap order of my_cxt_t/START_MY_CXT
- #define my_perl away under non-threaded perls
- make non-exported symbols static
- define a dummy openssl_threads_init() under non-threaded perls
Merge pull request #13 from mauke/fix-unthreaded

make SSH2.xs build under non-threaded perls
Merge pull request #12 from kmx/master

Win32 compatibility fix
update Changes with last two PRs
release 0.48