Import atf-0.18:

Experimental version released on November 16th, 2013.

• Issue 45: Added require.memory support in atf-run for FreeBSD.

• Fixed an issue with the handling of cin with libc++.

• Issue 64: Fixed various mandoc formatting warnings.

• X-NetBSD-PR bin/48284: Made atf-check flush its progress message to stdout so that an interrupted test case always shows the last message being executed.

• X-NetBSD-PR bin/48285: Fixed atf_check examples in atf-sh-api(3).

Approved by: rpaulo (mentor)