Make PAM version of logging in?

[ShadowKyogre]

I'm considering making a PAM version of NCDM to take advantage of the PAM modules, but I'm not exactly sure if I should go through with it. The feature set right now seems to be fine.

Possible provider of PAM support: https://launchpad.net/ubuntu/+source/python-pam
Patch for PAM that will have to be used to make this change official if decided: https://fedorahosted.org/linux-pam/ticket/9

[ShadowKyogre]

And the PAM variant works perfectly. Only question is if I should merge it into the master branch now.