The pthread API is considered a standard feature of libc so better to
simply merge it with the libc. Pthreads are in fact already a part of
the libc in the form of weak symbols. This merger is also a prerequisite
for better integrating pthreads with the libc I/O task.
Fix#3054
The new 'verify' component facilitates the code of GnuPG to verify
detached OpenPGP signatures against public keys.
Since GnuPG depends on libgcrypt and libgpg-error, the patch adds these
libraries to the libports repository.
Fixes#2640
