Changeset 1 in openpam

Import OpenPAM.

The basics (pam_start(), pam_end(), pam_strerror(), item-,
data- and environment-related functions and the six PAM
primitives) are implemented. A stub is provided for
pam_get_user(), which is not yet implemented. Stubs are also
provided for XSSO mapping and secondary authentication, though
they are not built and will probably not be implemented for
quite some time.

Sponsored by: DARPA, NAI Labs