-fix builds on FreeBSD 9,10 [1]
-temporarily mark WITH_THREADS as BROKEN on 9,10 [2]
-fix NOPORTDOCS; add a regression-test alias for the test
target; delay the patch clean-up to ease debugging; remove
some lines dealing with unsupported versions of FreeBSD

PR: 161502 [1], 162017 [2]
Submitted by: N. Toja [1,2]
Feature safe: yes