Detect lack of libpam-dev during configure.
Remove MONGO remnants from the pre-repo-split era.
Avoid spurious failures when rerunning the test due to socket not yet being released.
Merge pull request #1076 from jimis/varfix

Varfix
Made PAM detection more resilient, and catching some more errors.

Force PAM on platforms where it is known to exist, make it optional on
others. This also switches out the test for usermod tools with tests
for PAM instead.
Don't rely solely on PATH variable when configuring.
Bind to the port we mean.
Merge pull request #1077 from kacfengine/configure-fixes

Some fixes making pam detection more resilient.
Merge pull request #1078 from jimis/varfix2

Bind to the port we mean.
tag VerifyServices() as static to match prototype
Merge pull request #1079 from cdituri/cdituri/core/function-nitpick

tag VerifyServices() as static to match prototype
Make special detection macro for root binaries.

The tools that are detected by this macro are meant to be used at
run time, not build time, and therefore do not necessarily have
execute permission for ordinary users. Therefore we cannot use
AC_PATH_PROG.
Merge pull request #1081 from kacfengine/configure-fixes

Make special detection macro for root binaries.