Provide Pth compatiblity for use with GnuPG 2.0.
* src/ath.c (ath_install): Call ath_init and declare Pth as compatible.
GnuPG 2.0 requires GNU Pth which is a plain userland thread
implementation. Given that decent versions of GNU Pth seem to work
together with pthread, we can declare Pth as compatible. Native
pthreads in Libgcrypt are only used internal to Libgcrypt and any
internal blocking should be invisible to Pth.
- Signed-off-by: Werner Koch <wk@gnupg.org>